 Your new post is loading...
Your new post is loading...
Authors: Diego Alejandro Gutiérrez-Villamil, Stanislav Magnitskiy and Helber Enrique Balaguera-López.
Postharvest Biology and Technology (2024)
Highlights • BR have a potential signaling function in the regulation of fruit development. • BR are a postharvest technology to regulate the ripening of fruits and vegetables. • BR mitigate chilling injury by increasing antioxidant systems. • BR induce expression genes of defense and immunity against postharvest pathogens.
Abstract: "Fresh horticultural products satisfy the nutritional, and industrial needs of consumers worldwide. However, the lack of understanding of the fruit development process, the accelerated senescence process and the lack of post-harvest technology in some regions, present a threat to the food and economic security of the food agribusiness. Brassinosteroids (BR) are plant hormones involved in the regulation of various physiological processes and have recently proven to be a viable post-harvest technology alternative to regulate the ripening and senescence of fruits and vegetables. In this review, the current state of BR research on fruit growth and development, physicochemical changes during ripening, and biotic-abiotic stress during the post-harvest life of horticultural products is presented. Furthermore, the review encompasses the effect of the application of exogenous BR and its relationship with molecular signaling on the processes mentioned above, including aspects such as methods, moments and BR analogues at the time of application, and the molecular mechanisms involved. This review proposes a basis for research of the physiological aspects of BR regulation in fruits and vegetables during their development and post-harvest period, and also points to a direction for in-depth investigation of the molecular mechanisms."
Authors: Tomás Urzúa Lehuedé, Victoria Berdion Gabarain, Tomas Moyano, Lucia Ferrero, Miguel Angel Ibeas, Hernan Salinas-Grenet, Gerardo Núñez-Lillo, Romina Acha, Jorge Perez, Florencia Perotti, Virginia Natali Miguel, Fiorella Paola Spies, Miguel A. Rosas, Michitaro Shibata, Diana R. Rodríguez-García, Adrian A. Moreno, Keiko Sugimoto, Karen Sanguinet, Claudio Meneses, Raquel L. Chan, Federico Ariel, Jose M. Alvarez and José M. Estevez.
bioRxiv (2024)
Abstract: "The root hair (RH) cells can elongate to several hundred times their initial size, and are an ideal model system for investigating cell size control. Their development is influenced by both endogenous and external signals, which are combined to form a integrative response. Surprisingly, a low temperature condition of 10°C causes an increased RH growth in Arabidopsis and in several monocots, even when the development of the rest of the root and aerial parts of the plant are halted. Previously, we demonstrated a strong correlation between the growth response and a significant decrease in nutrient availability in the medium under low temperature conditions. However, the molecular basis responsible for receiving and transmitting signals related to the availability of nutrients in the soil, and their relation to plant development, remain largely unknown. We decided to further investigate the intricate molecular processes behind the particular responsiveness of this root cell type at low temperature. In this study, we have discovered a gene regulatory network (GRN) controlling early transcriptome responses to low temperature. This GNR is commanded by specific transcription factors (FTs), namely ROOT HAIR DEFECTIVE 6-LIKE 4 (RSL4), a member of the homeodomain leucine zipper (HD-Zip I) group I 13 (AtHB13), the trihelix TF GT2-LIKE1 (GTL1), and a previously unidentified MYB-like TF (AT2G01060). Furthermore, we have identified four downstream RSL4 targets AtHB16, AtHB23, EARLY-RESPONSIVE TO DEHYDRATION 7 (ERD7) and ERD10 suggesting their participation in the regulation of RH development under these conditions. Functional analysis shows that such components of the RSL4-dependent transcriptional cascade influence the subsequent RH growth response to low temperature. These discoveries enhance our comprehension of how plants synchronize the RH growth in response to variations in temperature and nutrient availability at the cellular level."
Author: Leiyun Yang
The Plant Cell (2024)
Excerpts: "Simultaneously, low temperature stimulates plant immunity by activating salicylic acid (SA)-mediated signaling (Wu et al. 2019). However, the mechanism by which plants integrate cold signals and immune signaling remain elusive. To investigate this question, Shaoqin Li and colleagues (Li et al. 2024) studied the potential involvement of ICE1 in cold-induced immunity in Arabidopsis."
"To elucidate how ICE1 regulates cold-induced immunity, the authors conducted a yeast-two-hybrid screen and identified NON-EXPRESSER OF PR GENES 1 (NPR1), a master transcriptional co-activator of PATHOGENESIS-RELATED GENE 1 (PR1) in SA-activated immunity, as an ICE1 interactor.....Additionally, the authors found that ICE1 directly binds to the PR1 promoter for gene activation. These results illustrate that ICE1 interacts with NPR1 and is required for SA-mediated immunity by directly promoting PR1 expression."
"These results support the conclusion that ICE1 and TGA3 work synergistically to promote PR1 transcription. This study not only shed light on a new role of ICE1 in SA-mediated immunity at low temperature, but also revealed NPR1-TGA3/ICE1 as an important nexus integrating SA signaling and cold signals in plant immunity (see Figure)."
Authors: Ruiqing Li, Yue Song, Xueqiang Wang, Chenfan Zheng, Bo Liu, Huali Zhang, Jian Ke, Xuejing Wu, Liquan Wu, Ruifang Yang and Meng Jiang.
Journal of Integrative Plant Biology (2024)
Editor's view: OsNAC5 regulates cold-responsive genes (CORs) to promote cold tolerance in rice via the OsABI5-CORs transcription module, constituting an exquisite regulatory cascade to responses to changing temperature conditions, which provides new insights for using molecular design breeding to improve cold tolerance in rice.
Abstract: "Due to its tropical origins, rice (Oryza sativa) is susceptible to cold stress, which poses severe threats to production. OsNAC5, a NAC-type transcription factor, participates in the cold stress response of rice, but the detailed mechanisms remain poorly understood. Here, we demonstrate that OsNAC5 positively regulates cold tolerance at germination and in seedlings by directly activating the expression of ABSCISIC ACID INSENSITIVE 5 (OsABI5). Haplotype analysis indicated that single nucleotide polymorphisms in a NAC-binding site in the OsABI5 promoter are strongly associated with cold tolerance. OsNAC5 also enhanced OsABI5 stability, thus regulating the expression of cold-responsive (COR) genes, enabling fine-tuned control of OsABI5 action for rapid, precise plant responses to cold stress. DNA affinity purification sequencing coupled with transcriptome deep sequencing identified several OsABI5 target genes involved in COR expression, including DEHYDRATION-RESPONSIVE ELEMENT BINDING FACTOR 1A (OsDREB1A), OsMYB20, and PEROXIDASE 70 (OsPRX70). In vivo and in vitro analyses suggested that OsABI5 positively regulates COR gene transcription, with marked COR upregulation in OsNAC5-overexpressing lines and downregulation in osnac5 and/or osabi5 knockout mutants. This study extends our understanding of cold tolerance regulation via OsNAC5 through the OsABI5-CORs transcription module, which may be used to ameliorate cold tolerance in rice via advanced breeding."
Authors: June-Sik Kim, Satoshi Kidokoro, Kazuko Yamaguchi-Shinozaki and Kazuo Shinozaki.
Plant Physiology (2024)
Abstract: "Drought and cold represent distinct types of abiotic stress, each initiating unique primary signaling pathways in response to dehydration and temperature changes, respectively. However, a convergence at the gene regulatory level is observed where a common set of stress-responsive genes is activated to mitigate the impacts of both stresses. In this review, we explore these intricate regulatory networks, illustrating how plants coordinate distinct stress signals into a collective transcriptional strategy. We delve into the molecular mechanisms of stress perception, stress signaling, and the activation of gene regulatory pathways, with a focus on insights gained from model species. By elucidating both the shared and distinct aspects of plant responses to drought and cold, we provide insight into the adaptive strategies of plants, paving the way for the engineering of stress-resilient crop varieties that can withstand a changing climate."
Authors: Yanmei Sun, Bohao Geng, Hongjian Sun, Juan You, Zhenfei Guo and Haifan Shi.
Environmental and Experimental Botany (2024)
Key Message: Overexpression of VsPYL5 led to increased salt and cold tolerance through improved expression of genes involved in Na+ and K+ homeostasis and ROS homeostasis and increased antioxidant defense capacity
Highlights: • Transgenic Arabidopsis overexpressing VsPYL5 had increased ABA sensitivity and enhanced salt and cold tolerance. • Transgenic lines had lower levels of Na+ but higher levels of K+ under salinity conditions. • Maintenance of ROS were associated with cold and salt tolerance in transgenic lines.
Abstract: "The pyrabactin resistance (PYR)/PYR-like (PYL)/regulatory component of ABA receptor (RCAR) proteins are the core components in ABA signaling pathway. A salt and cold induced ABA receptor gene VsPYL5 from common vetch was identified in the present study. Transgenic Arabidopsis overexpressing VsPYL5 had increased ABA sensitivity and higher levels of seed germination rate, survival rate, and the maximal photochemical efficiency of photosystem II (Fv/Fm) than the wild type (WT) under salinity conditions. Lower levels of the temperature that leads to 50% electrolyte leakage (TEL50) and higher levels of survival rate after freezing treatment were observed in transgenic lines compared with WT. The results indicated that VsPYL5 regulated salt and cold tolerance positively. Lower levels of Na+ and Na+/K+ ratio but higher levels of K+ and AKT1, GORK, KAT1, HKT1 and KUP4 transcripts were observed in transgenic lines compared with WT under salinity conditions. The results indicated that the increased salt tolerance in transgenic lines was associated with the altered Na+ and K+ levels as a result of improved expression of genes involved in Na+ and K+ homeostasis. Antioxidant enzyme activities and their encoding gene transcripts, proline concentration and reactive oxygen species (ROS) levels were increased after treatment with salinity or cold, with lower levels in transgenic lines compared with WT. It is suggested that VsPYL5-regulated salt and cold tolerance was associated with the increased proline level and antioxidant defense capacity for maintenance of ROS as a result of improved the relevant gene expression under salinity and cold conditions."
Authors: Jihong Li and Yuan Song.
Plant Science (2024)
Highlights: • The research of plant thermosensor is obviously lagging behind and hence has become an urgent problem to be resolved. • We summarized the recognized and potential plant thermosensors，to describe the multi–level thermal input system in plants. • We reviewed more recent thermosensing mechanisms to facilitate further understanding and studies.
Abstract: "Plants dynamically regulate their genes expression and physiological outputs to adapt to changing temperatures. The underlying molecular mechanisms have been extensively studied in diverse plants and in multiple dimensions. However, the question of exactly how temperature is detected at molecular level to transform the physical information into recognizable intracellular signals remains continues to be one of the undetermined occurrences in plant science. Recent studies have provided the physical and biochemical mechanistic breakthrough of how temperature changes can influence molecular thermodynamically stability, thus changing molecular structures, activities, interaction and signaling transduction. In this review, we focus on the thermosensing mechanisms of recognized and potential plant thermosensors, to describe the multi–level thermal input system in plants. We also consider the attributes of a thermosensor on the basis of thermal-triggered changes in function, structure, and physical parameters. This study thus provides a reference for discovering more plant thermosensors and elucidating plant thermal adaptive mechanisms."
Authors: Chaoyi Hu, Mengqi Wang, Changan Zhu, Shaofang Wu, Jiajia Li, Jingquan Yu and Zhangjian Hu.
Plant, Cell & Environment (2024)
Summary Statement: This study demonstrated that the cold- and abscisic acid (ABA)-responsive transcription factor ETHYLENE RESPONSE FACTOR 15 positively regulates ABA-mediated cold tolerance in tomato plants by activating CBF1 and WRKY6 expression.
Abstract: "Cold stress is a major meteorological threat to crop growth and yield. Abscisic acid (ABA) plays important roles in plant cold tolerance by activating the expression of cold-responsive genes; however, the underlying transcriptional regulatory module remains unknown. Here, we demonstrated that the cold- and ABA-responsive transcription factor ETHYLENE RESPONSE FACTOR 15 (ERF15) positively regulates ABA-mediated cold tolerance in tomato. Exogenous ABA treatment significantly enhanced cold tolerance in wild-type tomato plants but failed to rescue erf15 mutants from cold stress. Transcriptome analysis showed that ERF15 was associated with the expression of cold-responsive transcription factors such as CBF1 and WRKY6. Further RT-qPCR assays confirmed that the ABA-induced increased in CBF1 and WRKY6 transcripts was suppressed in erf15 mutants when the plants were subjected to cold treatment. Moreover, yeast one-hybrid assays, dual-luciferase assays and electrophoretic mobility shift assays demonstrated that ERF15 activated the transcription of CBF1 and WRKY6 by binding their promoters. Silencing CBF1 or WRKY6 significantly decreased cold tolerance. Overall, our study identified the role of ERF15 in conferring ABA-mediated cold tolerance in tomato plants by activating CBF1 and WRKY6 expression. This study not only broadens our knowledge of the mechanism of ABA-mediated cold tolerance in plants but also highlights ERF15 as an ideal target gene for cold-tolerant crop breeding."
Authors: Qiaoling Zheng, Qinhan Yu, Wenkong Yao, Kai Lv, Ningbo Zhang and Weirong Xu.
Journal of Agricultural and Food Chemistry (2023)
Abstract: "In globally cultivated grapevines, low-temperature stress poses a persistent challenge. Although COLD1 is recognized as a cold receptor in rice, its function in grapevine cold signaling is unclear. Here, we identified VaCOLD1, a transmembrane protein from the cold-tolerant Vitis amurensis Rupr, which is primarily located on plasma and endoplasmic reticulum membranes. Broadly expressed across multiple tissues, VaCOLD1 responds to various environmental stresses, particularly to cold. Its promoter contains distinct hormone- and stress-responsive elements, with GUS assays confirming widespread expression in Arabidopsis thaliana. Validation of interaction between VaCOLD1 and VaGPA1, together with their combined expression in yeast and grape calli, notably improved cold endurance. Overexpression of VaCOLD1 enhances cold tolerance in Arabidopsis by strengthening the CBF-COR signaling pathway. This is achieved through shielding against osmotic disturbances and modifying the expression of ABA-mediated genes. These findings emphasize the critical role of the VaCOLD1-VaGPA1 complex in mediating the response to cold stress via the CBF-COR pathway."
Authors: Huafeng Zhang, Yingping Pei, Feilong Zhu, Qiang He, Yunyun Zhou, Bohui Ma, Xiaoqing Chen, Jiangbai Guo, Abid Khan, Maira Jahangir, Lijun Ou and Rugang Chen.
The Plant Journal (2024)
Significance Statement: Abscisic acid (ABA) could be induced by cold stress, which can restrains the activity of PP2Cs to reduce the activity of CaSnRK2.4 kinase. CaSnRK2.4 can interact with and phosphorylate CaNAC035. CaNAC035 is induced by both cold and ABA treatments. Over expression of CaNAC035 resulted in enhanced cold stress tolerance, while knockdown of CaNAC035 significantly reduced resistance to cold stress. Additionally, CaNAC035 could bind to the promoters of CaNCED3 and CaAAO3, which led to the ABA accumulation.
Abstract: "Plant NAC transcription factors play a crucial role in enhancing cold stress tolerance, yet the precise molecular mechanisms underlying cold stress remain elusive. In this study, we identified and characterized CaNAC035, an NAC transcription factor isolated from pepper (Capsicum annuum) leaves. We observed that the expression of the CaNAC035 gene is induced by both cold and abscisic acid (ABA) treatments, and we elucidated its positive regulatory role in cold stress tolerance. Overexpression of CaNAC035 resulted in enhanced cold stress tolerance, while knockdown of CaNAC035 significantly reduced resistance to cold stress. Additionally, we discovered that CaSnRK2.4, a SnRK2 protein, plays an essential role in cold tolerance. In this study, we demonstrated that CaSnRK2.4 physically interacts with and phosphorylates CaNAC035 both in vitro and in vivo. Moreover, the expression of two ABA biosynthesis-related genes, CaAAO3 and CaNCED3, was significantly upregulated in the CaNAC035-overexpressing transgenic pepper lines. Yeast one-hybrid, Dual Luciferase, and electrophoretic mobility shift assays provided evidence that CaNAC035 binds to the promoter regions of both CaAAO3 and CaNCED3 in vivo and in vitro. Notably, treatment of transgenic pepper with 50 μm Fluridone (Flu) enhanced cold tolerance, while the exogenous application of ABA at a concentration of 10 μm noticeably reduced cold tolerance in the virus-induced gene silencing line. Overall, our findings highlight the involvement of CaNAC035 in the cold response of pepper and provide valuable insights into the molecular mechanisms underlying cold tolerance. These results offer promising prospects for molecular breeding strategies aimed at improving cold tolerance in pepper and other crops."
Authors: Jingqiu Xia, Jiawen Liang, Mengmeng Yu, Rui Wang, Chen Sun, Huishan Song, Qinghua Xu, Jing Cang, Yuying Wang and Da Zhang.
Environmental and Experimental Botany (2024)
Highlights • TaMED25 is involved in JA signal pathway. • TaMED25 expression responded to low temperature stress in wheat. • Overexpression of TaMED25 gene enhances freeze resistance in Arabidopsis plants. • TaMED25 is localized in the nucleus. • TaMED25 interacts with TaJAZ7, TaMYC2 and TaICE41 proteins.
Abstract: "The MEDIATOR (MED) complex is a molecular bridge that regulates transcription by connecting transcription factors (TFs) and specific gene promoters. The MED subunit 25 (MED25) can interact with specific TFs in the phytohormone signaling pathways to regulate the transcription of downstream genes and affect various physiological processes in plants. Although MED25 plays an important role in adaptation to abiotic stresses, it is still unclear whether MED25 is involved in freezing tolerance in wheat. In this study, we found that the expression of TaMED25 was significantly increased under extremely low temperatures (–25 °C) in Dongnongdongmai1 (Dn1) plants, a variety of winter wheat with excellent cold-stress resistance,and hypothesized that TaMED25 may be a novel regulator of freezing tolerance in this wheat variety. To further characterize the function of TaMED25 in freezing tolerance, we cloned TaMED25 from Dn1 plants and overexpressed it in Arabidopsis thaliana. The results showed that the overexpression of TaMED25 improved freezing tolerance in Arabidopsis plants, with decreased relative conductivity, enhanced ability to effectively scavenge reactive oxygen species (ROS), and increased expression of cold-responsive genes. Furthermore, we proposed that TaMED25 mediates jasmonate-induced cold resistance in plants, possibly by interacting with TaJAZ7 and TaMYC2 of the jasmonate signaling pathway and TaICE41 of the ICE–CBF–COR pathway. Our findings reveal the functions of MED25 in plants and provide a scientific basis for an in-depth analysis of the transcriptional regulation mechanism of freezing tolerance in winter wheat."
Authors: Lihui Wang, Hui Chen, Guoyu Chen, Guangbao Luo, Xinyan Shen, Bo Ouyang and Zhilong Bie.
Plant Physiology (2023)
Abstract: "Tomato (Solanum lycopersicum) is a cold-sensitive crop but frequently experiences low-temperature stimuli. However, tomato responses to cold stress are still poorly understood. Our previous studies have shown that using wild tomato (S. habrochaites) as rootstock can significantly enhance the cold resistance of grafted seedlings, in which a high concentration of jasmonates (JAs) in scions exerts an important role, but the mechanism of JA accumulation remains unclear. Herein, we discovered that tomato SlWRKY50, a group II WRKY transcription factor that is cold-inducible, responds to cold stimuli and plays a key role in JA biosynthesis. SlWRKY50 directly bound to the promoter of tomato allene oxide synthase gene (SlAOS), and overexpressing SlWRKY50 improved tomato chilling resistance, which led to higher levels of Fv/Fm, antioxidative enzymes, SlAOS expression, and JA accumulation. SlWRKY50-silenced plants, however, exhibited an opposite trend. Moreover, DIECA (a JA biosynthesis inhibitor) foliar treatment drastically reduced the cold tolerance of SlWRKY50-OE plants to WT levels. Importantly, SlMYC2, the key regulator of the JA signaling pathway, can control SlWRKY50 expression. Overall, our research indicates that SlWRKY50 promotes cold tolerance by controlling JA biosynthesis and that JA signaling mediates SlWRKY50 expression via transcriptional activation by SlMYC2. Thus, this contributes to the genetic knowledge necessary for developing cold-resistant tomato varieties."
Authors: Zixi Liu, Ying Chen, Qinglin Xiang, Tao Wang, Lihong Gao and Wenna Zhang.
Vegetable Research (2023)
Abstract: "Low temperature stress has severe detrimental effects on plant growth and crop yield. While the role of phytohormone ABA in regulating cold stress tolerance has been recognized, its underlying regulation mechanisms remain poorly understood. Here, we investigate the involvements of SlMETS1 (Methionine Synthase 1) and SlABO5/6 (ABA Overly-Sensitive 5/6) in response to low temperature stress, and their reliance on the abscisic acid (ABA) pathways using wild-type tomato (WT) and ABA defective mutants not (notabilis) and sit (sitiens). Our findings reveal that cold stress influences the expression of SlMETS1, SlABO5, and SlABO6. The sit mutant exhibits similar expression tendency to the WT. However, the not mutant shows distinctive expression patterns of these three genes. In fact, they respond more rapidly and earlier to cold stress in not compared to the WT and sit. SlMETS1 inhibition by virus-induced gene silencing (VIGS) leads to cold stress sensitivity, resembling ABA defective mutants. These discoveries suggest an association of SlMETS1, SlABO5, and SlABO6 with SlNCED in the ABA biosynthesis and signaling pathways during cold stress, providing new molecular evidence for the relevance between methionine synthesis, ABA signaling, cold tolerance and shoot-root communication in plants."
|
Authors: Rui Yan, Tianle Zhang, Yuan Wang, Wenxiu Wang, Rahat Sharif, Jiale Liu, Qinglong Dong, Haoan Luan, Xuemei Zhang, Han Li, Suping Guo, Guohui Qi and Peng Jia.
Plant Physiology and Biochemistry (2024)
Highlights: • Seventeen GA2-oxidase genes identified in apple clustered into four clades. • MdGA2ox7 responded to cold and salt treatments. • MdGA2ox7 was activated during light-induced anthocyanin accumulation. • MdGA2ox7 alleviated cold and salt stress damage. • MdGA2ox7 promoted anthocyanin biosynthesis.
Abstract: "Apple (Malus domestica Borkh.) is a widely cultivated fruit crop worldwide but often suffers from abiotic stresses such as salt and cold. Gibberellic acid (GA) plays a pivotal in controlling plant development, environmental adaptability, and secondary metabolism. The GA2-oxidase (GA2ox) is responsible for the deactivation of bioactive GA. In this study, seventeen GA2-oxidase genes were identified in the apple genome, and these members could be clustered into four clades based on phylogenetic relationships and conserved domain structures. MdGA2ox7 exhibited robust expression across various tissues, responded to cold and salt treatments, and was triggered in apple fruit peels via light-induced anthocyanin accumulation. Subcellular localization prediction and experiments confirmed that MdGA2ox7 was located in the cytoplasm. Overexpression of MdGA2ox7 in Arabidopsis caused a lower level of active GA and led to GA-deficient phenotypes, such as dwarfism and delayed flowering. MdGA2ox7 alleviated cold and salt stress damage in both Arabidopsis and apple in concert with melatonin (MT). Additionally, MdGA2ox7 enhanced anthocyanin biosynthesis in apple calli and activated genes involved in anthocyanin synthesis. These findings provide new insights into the functions of apple GA2ox in regulating development, stress tolerance, and secondary metabolism."
Authors: Tao Wang, Xuemin Ma, Ying Chen, Cuicui Wang, Zhenxiao Xia, Zixi Liu, Lihong Gao and Wenna Zhang.
Plant, Cell & Environment (2024)
Abstract: "Low temperature stress poses a significant challenge to the productivity of horticultural crops. The dynamic expression of cold-responsive genes plays a crucial role in plant cold tolerance. While NAC transcription factors have been extensively studied in plant growth and development, their involvement in regulating plant cold tolerance remains poorly understood. In this study, we focused on the identification and characterisation of SlNAC3 as the most rapid and robust responsive gene in tomato under low temperature conditions. Manipulating SlNAC3 through overexpression or silencing resulted in reduced or enhanced cold tolerance, respectively. Surprisingly, we discovered a negative correlation between the expression of CBF and cold tolerance in the SlNAC3 transgenic lines. These findings suggest that SlNAC3 regulates tomato cold tolerance likely through a CBF-independent pathway. Furthermore, we conducted additional investigations to identify the molecular mechanisms underlying SlNAC3-mediated cold tolerance in tomatoes. Our results revealed that SlNAC3 controls the transcription of ethylene biosynthetic genes, thereby bursting ethylene release in response to cold stress. Indeed, the silencing of these genes led to an augmentation in cold tolerance. This discovery provides valuable insights into the regulatory pathways involved in ethylene-mediated cold tolerance in tomatoes, offering potential strategies for developing innovative approaches to enhance cold stress resilience in this economically important crop species."
Authors: Shaoqin Li, Li He, Yongping Yang, Yixin Zhang, Xiao Han, Yanru Hu and Yanjuan Jiang.
The Plant Cell (2024)
One-sentence summary: The NPR1–TGA3–ICE1 regulatory module represents an important step in salicylic acid signaling during cold-activated resistance of plants to pathogen attack.
Abstract: "Cold stress affects plant immune responses, and this process may involve the salicylic acid (SA) signaling pathway. However, the underlying mechanism by which low-temperature signals coordinate with SA signaling to regulate plant immunity remains unclear. Here, we found that low temperatures enhanced the disease resistance of Arabidopsis thaliana against Pseudomonas syringae pv. tomato DC3000. This process required INDUCER OF CBF EXPRESSION 1 (ICE1), the core transcription factor in cold-signal cascades. ICE1 physically interacted with NONEXPRESSER OF PATHOGENESIS-RELATED GENES 1 (NPR1), the master regulator of the SA signaling pathway. Enrichment of ICE1 on the PATHOGENESIS-RELATED GENE 1 (PR1) promoter and its ability to transcriptionally activate PR1 were enhanced by NPR1. Further analyses revealed that cold stress signals cooperate with SA signals to facilitate plant immunity against pathogen attack in an ICE1-dependent manner. Cold treatment promoted interactions of NPR1 and TGACG-BINDING FACTOR 3 (TGA3) with ICE1 and increased the ability of the ICE1–TGA3 complex to transcriptionally activate PR1. Together, our results characterize a critical role of ICE1 as an indispensable regulatory node linking low-temperature-activated and SA-regulated immunity. Understanding this crucial role of ICE1 in coordinating multiple signals associated with immunity broadens our understanding of plant–pathogen interactions."
Abstract: "Cold stress severely restricts growth and development, reduces yields, and impairs quality in tomatoes (Solanum lycopersicum). Amylase-associated starch degradation and soluble sugar accumulation have been implicated in adaptation and resistance to abiotic stress. Here, we report a β-amylase (BAM) gene, SlBAM3, which plays a central role in tomato cold tolerance. The expression of SlBAM3 was triggered by cold stress. SlBAM3 knockout using the CRISPR/Cas9 system retarded starch degradation and reduced soluble sugar accumulation in tomato plants, eventually attenuating cold tolerance. Expression analysis revealed that the SlBAM3 transcript level was boosted by MeJA. Furthermore, MYC2, an essential component of the JA signaling pathway, could bind to the SlBAM3 promoter and directly activate SlBAM3 transcription, as revealed by yeast one-hybrid and dual LUC assays. In addition, the suppression of MYC2 resulted in increased starch accumulation, decreased soluble sugar content, and reduced tolerance to cold stress in tomato plants. Taken together, these findings demonstrate that JA positively regulates β-amylase-associated starch degradation through the MYC2-SlBAM3 module in tomato during cold stress. The results of the present work expand our understanding of the mechanisms underlying BAM gene activation and starch catabolism under cold stress. The regulatory module of SlBAM3 can be further utilized to breed tomato cultivars with enhanced cold tolerance."
Authors: Mingjuan Zhai, Yating Chen, Xiaowu Pan, Ying Chen, Jiahao Zhou, Xiaodan Jiang, Zhijin Zhang, Guiqing Xiao and Haiwen Zhang.
Plant, Cell & Environment (2024)
One-sentence summary: The OsEIN2-OsEIL1/2 ethylene pathway has negative effect on rice tolerance to low temperature stress through transcriptionally repressing OsICE1-mediated chilling response.
Abstract: "Low temperature severely affects rice development and yield. Ethylene signal is essential for plant development and stress response. Here, we reported that the OsEIN2-OsEIL1/2 pathway reduced OsICE1-dependent chilling tolerance in rice. The overexpressing plants of OsEIN2, OsEIL1 and OsEIL2 exhibited severe stress symptoms with excessive reactive oxygen species (ROS) accumulation under chilling, while the mutants (osein2 and oseil1) and OsEIL2-RNA interference plants (OsEIL2-Ri) showed the enhanced chilling tolerance. We validated that OsEIL1 and OsEIL2 could form a heterodimer and synergistically repressed OsICE1 expression by binding to its promoter. The expression of OsICE1 target genes, ROS scavenging- and photosynthesis-related genes were downregulated by OsEIN2 and OsEIL1/2, which were activated by OsICE1, suggesting that OsEIN2-OsEIL1/2 pathway might mediate ROS accumulation and photosynthetic capacity under chilling by attenuating OsICE1 function. Moreover, the association analysis of the seedling chilling tolerance with the haplotype showed that the lower expression of OsEIL1 and OsEIL2 caused by natural variation might confer chilling tolerance on rice seedlings. Finally, we generated OsEIL2-edited rice with an enhanced chilling tolerance. Taken together, our findings reveal a possible mechanism integrating OsEIN2-OsEIL1/2 pathway with OsICE1-dependent cascade in regulating chilling tolerance, providing a practical strategy for breeding chilling-tolerant rice."
Authors: Jana Jarošová, Sylva Prerostova, Martin Černý, Petre Dobrev, Alena Gaudinova, Vojtech Knirsch, Eva Kobzová, Karel Müller, Roman Fiala, Kinga Benzcúr, Gabriella Szalai, Jan Novák, Břetislav Brzobohatý, Ondrej Novak and Radomira Vankova.
Environmental and Experimental Botany (2024)
Highlights: • Targeted stresses affected proteins predominantly in the non-exposed organs • Abscisic acid in roots after all cold treatments regulated hydraulic conductivity • Jasmonates in stressed leaves might diminish stress effects on photosynthesis • Salicylic acid probably enhanced sugar unloading from phloem in roots under stress • Pre-acclimation enhanced stress tolerance, and speeded up recovery
Abstract: "Rice is a plant species sensitive to cold stress, which renders seriously its cultivation. Responses to cold stress (5°C, 24 hours) in whole plants, or targeted to rice leaves or roots were followed at the hormonome, transcriptome, proteome, and sugar levels, to find organ-specific responses and processes affected by cold acclimation. Targeted stresses caused proteomic changes mainly in the unexposed organs. An increase in abscisic acid (ABA) was accompanied by a decrease in jasmonic acid (JA) (in roots and non-stressed leaves) and vice versa (JA increased in stressed leaves). Both hormones promote the cold tolerance of plants. In this way, JA could indirectly reduce negative effects of cold on photosynthesis in leaves, while ABA dominates in roots (stimulation of protective substances, especially dehydrins, control of water regime). The decrease in cytokinins trans-zeatin and dihydrozeatin in crowns correlated with stress-induced growth suppression. Leaf-targeted cold stress impaired photosynthesis and decreased sugar levels, diminishing their transport, which correlated with an increase in salicylic acid, which is a signal for sugar unloading from phloem into roots. Root-targeted stress suppressed cytokinin biosynthesis and upward transport, and promoted sugar accumulation in leaves. Acclimation per se activated the transcriptome and proteome response to cold –ABA, JA and ethylene were upregulated, moderately suppressing plant growth. Pre-acclimated plants showed less profound hormonal changes than directly stressed plants, positively affecting levels of growth-related phytohormones in the unexposed organs (cytokinins in roots of leaf-stressed plants; auxins in leaves of root-stressed plants)."
Authors: Chuanzhong Zhang, Hongru Wang, Xiaojie Tian, Xinyan Lin, Yunfei Han, Zhongmin Han, Hanjing Sha, Jia Liu, Jianfeng Liu, Jian Zhang, Qingyun Bu and Jun Fang.
Nature Communications (2024)
Editor´s view: Japonica rice generally has greater capacity for low temperatures germination (LTG) than indica rice. Here, the authors report an E2 ubiquitin-conjugating enzyme-encoding gene OsUBC12 can increase LTG in japonica rice by negatively regulate ABA signaling via promoting the proteasomal degradation of OsSnRK1.1.
Abstract: "Low-temperature germination (LTG) is an important agronomic trait for rice (Oryza sativa). Japonica rice generally has greater capacity for germination at low temperatures than the indica subpopulation. However, the genetic basis and molecular mechanisms underlying this complex trait are poorly understood. Here, we report that OsUBC12, encoding an E2 ubiquitin-conjugating enzyme, increases low-temperature germinability in japonica, owing to a transposon insertion in its promoter enhancing its expression. Natural variation analysis reveals that transposon insertion in the OsUBC12 promoter mainly occurs in the japonica lineage. The variation detected in eight representative two-line male sterile lines suggests the existence of this allele introgression by indica-japonica hybridization breeding, and varieties carrying the japonica OsUBC12 locus (transposon insertion) have higher low-temperature germinability than varieties without the locus. Further molecular analysis shows that OsUBC12 negatively regulate ABA signaling. OsUBC12-regulated seed germination and ABA signaling mainly depend on a conserved active site required for ubiquitin-conjugating enzyme activity. Furthermore, OsUBC12 directly associates with rice SUCROSE NON-FERMENTING 1-RELATED PROTEIN KINASE 1.1 (OsSnRK1.1), promoting its degradation. OsSnRK1.1 inhibits LTG by enhancing ABA signaling and acts downstream of OsUBC12. These findings shed light on the underlying mechanisms of UBC12 regulating LTG and provide genetic reference points for improving LTG in indica rice."
Authors: Junduo Li, Kai Lv, Jieping Wu, Yaping Xie, Junxia Zhang, Ningbo Zhang and Weirong Xu.
Journal of Agricultural and Food Chemistry (2023)
Abstract: "Melatonin (MEL) is an antioxidant molecule that enhances plant tolerance to environmental stress. However, the mechanisms by which MEL regulates cold signaling pathways in grapes under cold stress remain elusive. Here, we investigated the physiological and transcriptomic changes in grape seedlings treated with exogenous MEL to determine their protective role under cold stress. Results showed that 150 μM MEL effectively attenuated cold-induced cell damage by reducing reactive oxygen species (ROS) and preserving the chloroplast structure and function. MEL also inhibited tannin degradation, which contributed to its protective effect. Exogenous MEL promoted the synthesis of endogenous MEL, abscisic acid, auxin, and cytokinin while inhibiting gibberellin. Transcriptomic profiling revealed 776 differentially expressed transcripts in MEL-treated samples compared to controls. Functional analysis of a candidate hub gene, VvHSFA6b, showed that its overexpression in grape calli enhances cold tolerance by activating jasmonic acid synthesis pathway genes, promoting JA accumulation, and inhibiting JAZ-repressed transcription factors."
Authors: Manvi Sharma and Petra Marhava.
Current Opinion in Plant Biology (2023)
Abstract: "Plants have evolved robust adaptive mechanisms to withstand the ever-changing environment. Tightly regulated distribution of the hormone auxin throughout the plant body controls an impressive variety of developmental processes that tailor plant growth and morphology to environmental conditions. The proper flow and directionality of auxin between cells is mainly governed by asymmetrically localized efflux carriers – PINs – ensuring proper coordination of developmental processes in plants. Discerning the molecular players and cellular dynamics involved in the establishment and maintenance of PINs in specific membrane domains, as well as their ability to readjust in response to abiotic stressors is essential for understanding how plants balance adaptability and stability. While much is known about how PINs get polarized, there is still limited knowledge about how abiotic stresses alter PIN polarity by acting on these systems. In this review, we focus on the current understanding of mechanisms involved in (re)establishing and maintaining PIN polarity under abiotic stresses."
Authors: Chong Yang, Huihui Wang, Qiqi Ouyang, Guo Chen, Xiaoyu Fu, Dianyun Hou and Huawei Xu.
Plants (2023)
Abstract: "Significant progress has been made in the functions of auxin efflux transporter PIN-FORMED (PIN) genes for the regulation of growth and development in rice. However, knowledge on the roles of OsPIN genes in abiotic stresses is limited. We previously reported that the mutation of OsPIN1b alters rice architecture and root gravitropism, while the role of OsPIN1b in the regulation of rice abiotic stress adaptations is still largely elusive. In the present study, two homozygous ospin1b mutants (C1b-1 and C1b-2) were employed to investigate the roles of OsPIN1b in regulating abiotic stress adaptations. Low temperature gradually suppressed OsPIN1b expression, while osmotic stress treatment firstly induced and then inhibited OsPIN1b expression. Most OsPIN genes and auxin biosynthesis key genes OsYUC were up-regulated in ospin1b leaves, implying that auxin homeostasis is probably disturbed in ospin1b mutants. The loss of function of OsPIN1b significantly decreased rice chilling tolerance, which was evidenced by decreased survival rate, increased death cells and ion leakage under chilling conditions. Compared with the wild-type (WT), ospin1b mutants accumulated more hydrogen peroxide (H2O2) and less superoxide anion radicals (O−2) after chilling treatment, indicating that reactive oxygen species (ROS) homeostasis is disrupted in ospin1b mutants. Consistently, C-repeat binding factor (CBF)/dehydration-responsive element binding factor (DREB) genes were downregulated in ospin1b mutants, implying that OsDREB genes are implicated in OsPIN1b-mediated chilling impairment. Additionally, the mutation of OsPIN1b led to decreased sensitivity to abscisic acid (ABA) treatment in seed germination, impaired drought tolerance in the seedlings and changed expression of ABA-associated genes in rice roots. Taken together, our investigations revealed that OsPIN1b is implicated in chilling and drought tolerance in rice and provide new insight for improving abiotic stress tolerance in rice."
Authors: Jingye Fu, Wenzheng Pei, Linqian He, Ben Ma, Chen Tang, Li Zhu, Liping Wang, Yuanyuan Zhong, Gang Chen, Qi Wang and Qiang Wang.
PLoS Genetics (2023)
Abstract: "Rapid and uniform seed germination is required for modern cropping system. Thus, it is important to optimize germination performance through breeding strategies in maize, in which identification for key regulators is needed. Here, we characterized an AP2/ERF transcription factor, ZmEREB92, as a negative regulator of seed germination in maize. Enhanced germination in ereb92 mutants is contributed by elevated ethylene signaling and starch degradation. Consistently, an ethylene signaling gene ZmEIL7 and an α-amylase gene ZmAMYa2 are identified as direct targets repressed by ZmEREB92. OsERF74, the rice ortholog of ZmEREB92, shows conserved function in negatively regulating seed germination in rice. Importantly, this orthologous gene pair is likely experienced convergently selection during maize and rice domestication. Besides, mutation of ZmEREB92 and OsERF74 both lead to enhanced germination under cold condition, suggesting their regulation on seed germination might be coupled with temperature sensitivity. Collectively, our findings uncovered the ZmEREB92-mediated regulatory mechanism of seed germination in maize and provide breeding targets for maize and rice to optimize seed germination performance towards changing climates."
Authors: Juraj Kleman and Radoslava Matusova
Biologia (2023)
Abstract: "The discovery of strigolactones has resulted in a confluence of various research topics like parasitic plants, arbuscular mycorrhizal fungi and phytohormones, which all play a big role in current global agricultural production. Over the past few decades, strigolactone research swiftly gained a spotlight, as to reveal their possible functions within plants and also the surrounding organisms in the rhizosphere. In this review, we explore the discovered functions of strigolactones with the main focus on the chemical structure of strigolactones and how it relates to the various biological responses they cause. We highlight their involvement in plant responses to abiotic stressors, like lack of available nutrients, high salinity, drought, extreme temperatures and presence of potentially toxic elements of environmental importance, while reflecting upon the strigolactone-mediated plant associations with arbuscular mycorrhizal fungi and nodule-forming, N-fixing bacteria. Furthermore, we elaborate on the current state of applied strigolactone research in agriculture and the probable bright future these compounds have in commercial use and what hurdles need to be overcome before they can be fully utilized."
|
