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How to use this site to your advantage ... and not get lost
How to benefit the most of this site?
Just follow the steps as below:
- The first possibility (and a highly recommended one) is just to visit it frequently, in order to stay aware of the newly published articles or sources of information as soon as they are posted.
- Further, since the most recent 4,520 postings from the total of 8,080 originally posted are presently available (as of May 19, 2024) and arranged as per date of posting, you can do a search according to your specific interests. In doing that, you go to the upper right corner ("Search in topic" depicted with a label), where you can just use the descriptors that are available there, i.e. "Tags", which are ordered alphabetically. Another possibility is to type there a keyword (or an entire phrase) that can be the name of an author or a word/phrase contained in the title/abstract or anything you deem relevant. That way you will be shown a reduced number of sources being more relevant to your specific interest(s).
Hoping this will be useful and waiting for feedback to keep improving the site, I wish all the best
Julio Retamales (the curator)
NOTE: Certainly, given the sheer number of articles being published currently on the relevant issues, no claim for completeness can be provided. Therefore, only samples of papers and/or sources arbitrarily selected by the curator are posted here, intending to show the diversity of phenomena in which plant hormones can be involved.
Authors: Ruxue Bao, Changying Zeng, Ke Li, Mengtao Li, Yajun Li, Xincheng Zhou, Haiyan Wang, Yajie Wang, Dongyi Huang, Wenquan Wang and Xin Chen.
The Plant Journal (2024)
Significance Statement: Schematic of the increase in cellulose synthesis and active gibberellin content to promote cell enlargement via the modulation of MeGT2.6. UDP-Glc: Uridine diphosphate glucose; CSC: cellulose synthase complex; SCW: secondary cell wall. Cassava is a tropical root crop with huge biomass. Increasing the allocation of photoassimilate to the sink organ can enhance the yield of storage root. MeGT2.6 is a multi-regulatory factor regulating plant growth and development, and carbon source allocation. Its mutant can be created by gene editing, thereby providing an important germplasm resource for breeding new cassava varieties with dwarf property and high starch yield.
Abstract: "Cassava, a pivotal tropical crop, exhibits rapid growth and possesses a substantial biomass. Its stem is rich in cellulose and serves as a crucial carbohydrate storage organ. The height and strength of stems restrict the mechanised operation and propagation of cassava. In this study, the triple helix transcription factor MeGT2.6 was identified through yeast one-hybrid assay using MeCesA1pro as bait, which is critical for cellulose synthesis. Over-expression and loss-of-function lines were generated, and results revealed that MeGT2.6 could promote a significant increase in the plant height, stem diameter, cell size and thickness of SCW of cassava plant. Specifically, MeGT2.6 upregulated the transcription activity of MeGA20ox1 and downregulated the expression level of MeGA2ox1, thereby enhancing the content of active GA3, resulting in a large cell size, high plant height and long stem diameter in cassava. Moreover, MeGT2.6 upregulated the transcription activity of MeCesA1, which promoted the synthesis of cellulose and hemicellulose and produced a thick secondary cell wall. Finally, MeGT2.6 could help supply additional substrates for the synthesis of cellulose and hemicellulose by upregulating the invertase genes (MeNINV1/6). Thus, MeGT2.6 was found to be a multiple regulator; it was involved in GA metabolism and sucrose decomposition and the synthesis of cellulose and hemicellulose."
Authors: Qian Li, Juan Wang, Zhaonan Yin, Yingfang Pan, Wei Mao, Liangyu Peng, Xinyue Guo, Bao Li and Ping Leng.
The Plant Journal (2024)
Significance Statement: SlPP2C2 regulates tomato development by integrating ABA and auxin signals through interaction with FZY/SAUR. This finding extends our knowledge of ABA signal cross talk in regulation of tomato development.
Abstract: "Abscisic acid (ABA) signaling interacts frequently with auxin signaling when it regulates plant development, affecting multiple physiological processes; however, to the best of our knowledge, their interaction during tomato development has not yet been reported. Here, we found that type 2C protein phosphatase (SlPP2C2) interacts with both flavin monooxygenase FZY, an indole-3-acetic acid (IAA) biosynthetic enzyme, and small auxin upregulated RNA (SAUR) of an IAA signaling protein and regulates their activity, thereby affecting the expression of IAA-responsive genes. The expression level of SlPP2C2 was increased by exogenous ABA, IAA, NaCl, or dehydration treatment of fruits, leaves, and seeds, and it decreased in imbibed seeds. Manipulating SlPP2C2 with overexpression, RNA interference, and CRISPR/Cas9-mediated genome editing resulted in pleiotropic changes, such as morphological changes in leaves, stem trichomes, floral organs and fruits, accompanied by alterations in IAA and ABA levels. Furthermore, the RNA-seq analysis indicated that SlPP2C2 regulates the expression of auxin-/IAA-responsive genes in different tissues of tomato. The results demonstrate that SlPP2C2-mediated ABA signaling regulates the development of both vegetative and reproductive organs via interaction with FZY/SAUR, which integrates the cross-talk of ABA and auxin signals during development and affects the expressions of development-related genes in tomato."
Authors: Duc Thinh Khong, Kien Van Vu, Benny Jian Rong Sng, Ian Kin Yuen Choi, Thomas K. Porter, Jianqiao Cui, Xun Gong, Song Wang, Nguyen Hoai Nguyen, Mervin Ang, Minkyung Park, Tedrick Thomas Salim Lew, Suh In Loh, Riza Ahsim, Hui Jun Chin, Gajendra Pratap Singh, Mary B. Chan-Park, Nam-Hai Chua, Michael S. Strano and In-Cheol Jang.
bioRxiv (2024)
Abstract: "Auxins, particularly indole-3-acetic acid (IAA), is a phytohormone critical for plant growth, development, and response to environmental stimuli. Despite its importance, there is a lack of species-independent sensors that allow direct and reversible detection of IAA. Herein, we introduce a novel near infrared fluorescent nanosensor for spatial and temporal measurement of IAA in planta using Corona Phase Molecular Recognition. The IAA nanosensor shows high specificity to IAA in vitro and was validated to localize and function in plant cells. The sensor works across different plant species without optimization and allows visualization of dynamic changes to IAA distribution and movement in leaf tissues. The results highlighted the utility of IAA nanosensor for understanding IAA dynamics in planta."
Authors: Hiromitsu Tabeta and Masami Y. Hirai.
FEBS Letters (2024)
Summary: Here, we identified l-2-aminopimelic acid as a novel functional amino acid that promotes high lateral root density. By adding this amino acid, the root system in a wide range of dicotyledonous plant species was converted from a primary-lateral root system to a fibrous root-like system.
Abstract: "The identification of chemicals that modulate plant development and adaptive responses to stresses has attracted increasing attention for agricultural applications. Recent basic studies have identified functional amino acids that are essential for plant organogenesis, indicating that amino acids can regulate plant growth. In this study, we newly identified 2-aminopimelic acid (2APA), a nonproteinogenic amino acid, as a novel bioactive compound involved in root morphogenesis. This biological effect was confirmed in several plant species. Our phenotypic analysis revealed that the bioactive 2APA is an L-form stereoisomer. Overall, our study identified a promising root growth regulator and provided insight into the intricate metabolism related to root morphology."
Authors: Yuqi Liu, Shangyu Chen, Sikander Pal, Jingquan Yu, Yanhong Zhou, Lam-Son Phan Tran and Xiaojian Xia.
New Crops (2024)
Abstract: "Plants have evolved varied structures for environmental adaptation. Shoot branching, as a part of plant architecture, influences the allocation of sugars produced by photosynthesis and thus greatly impacts crop yields. The activity of axillary meristem, and apical dominance governs the shoot branching patterns. In this review, we summarize the key factors involved in the formation of lateral branches, and the mechanisms of how these factors are interconnected. In particular, we focus on recent advances in understanding how sugar and environmental signals affect the hormonal signaling network to regulate apical dominance. Ultimately, we propose that epigenetic modifications are critical mechanisms underlying the plasticity of shoot branching, and that precise targeted gene editing is promising for shaping the ideal plant architecture."
Authors: Qingjun Xie, Danni Wang, Yuting Ding, Wenshuo Gao, Jinghang Li, Chuanwang Cao, Lili Sun, Zhongyuan Liu and Caiqiu Gao.
Science of the Total Environment (2024)
Highlights: • Various plant hormones play roles in the accumulation of Cd in T. hispida. • ABA and ethylene antagonistic regulation of Cd accumulation in T. hispida • ThDRE1A regulates Cd accumulation by regulating ThABAH2.5 and ThACCO3.1.
Abstract: "Tamarix hispida is highly tolerant to salt, drought and heavy metal stress and is a potential material for the remediation of cadmium (Cd)-contaminated soil under harsh conditions. In this study, T. hispida growth and chlorophyll content decreased, whereas flavonoid and carotenoid contents increased under long-term Cd stress (25 d). The aboveground components of T. hispida were collected for RNA-seq to investigate the mechanism of Cd accumulation. GO and KEGG enrichment analyses revealed that the differentially expressed genes (DEGs) were significantly enriched in plant hormone-related pathways. Exogenous hormone treatment and determination of Cd2+ levels showed that ethylene (ETH) and abscisic acid (ABA) antagonists regulate Cd accumulation in T. hispida. Twenty-five transcription factors were identified as upstream regulators of hormone-related pathways. ThDRE1A, which was previously identified as an important regulatory factor, was selected for further analysis. The results indicated that ThABAH2.5 and ThACCO3.1 were direct target genes of ThDRE1A. The determination of Cd2+, ABA, and ETH levels indicated that ThDRE1A plays an important role in Cd accumulation through the antagonistic regulation of ABA and ethylene. In conclusion, these results reveal the molecular mechanism underlying Cd accumulation in plants and identify candidate genes for further research."
Author: Munkhtsetseg Tsednee.
Plant Physiology (2024)
Excerpts: "In this issue of Plant Physiology, Wu et al. (2024) investigated the N responses in two maize lines, and identified a transcription factor (TF) involved in the regulation of nitrate uptake. First, the authors looked at gene expression in response to nitrogen recovery after depletion. By correlating gene co-expression network data with nitrate supplied time points, they successfully identified four consensus N-related modules conserved in two representative maize lines, B73 and Mo17."
"Moreover, zmereb97 mutants accumulate biomass more slowly than wild-type plants both under nitrate-limited and fully nitrate-supplied conditions, and mutants produce less grains, with 13 to 15% reductions in grain yields compared to wild-type plants under soil growth conditions (Fig. A and B)."
"To reveal how ZmEREB97 regulates nitrate uptake, the authors conducted yeast one hybrid assays using 17 selected nitrate transporter (NRT) genes potentially regulated by ZmEREB97 and showed that six ZmNRTs interact with ZmEREB97 via GCC-elements in their promoters for transcriptional activation. These six are the transporters mainly responsible for the nitrate uptake from soil (Fig. C). Direct controlling of uptake transporters is vital in that it is the primary source of nutrients into roots. Therefore, Wu et al. (2024) have identified a critical player, ZmEREB97, as a major positive regulator in nitrate response in maize."
Authors: Pierre Gautrat, Sanne E. A. Matton, Lisa Oskam, Siddhant S. Shetty, Kyra J. van der Velde and Ronald Pierik.
Journal of Experimental Botany (2024)
Abstract: "Plants growing in dense vegetation stands need to flexibly position their photosynthetic organs to ensure optimal light capture in a competitive environment. They do so through a suite of developmental responses referred to as the shade avoidance syndrome. Belowground, root development is also adjusted in response to aboveground neighbour proximity. Canopies are dynamic and complex environments with heterogeneous light cues in the far-red, red, blue and UV spectrum, which can be perceived with photoreceptors by spatially separated plant tissues. Molecular regulation of plant architecture adjustment via PHYTOCHROME-INTERACTING FACTOR (PIF) transcription factors and growth-related hormones such as auxin, gibberellic acid, brassinosteroids and abscisic acid were historically studied without much attention to spatial or tissue-specific context. Recent developments and technologies have, however, sparked strong interest in spatially explicit understanding of shade avoidance regulation. Other environmental factors such as temperature and nutrient availability interact with the molecular shade avoidance regulation network, often depending on the spatial location of the signals, and the responding organs. Here, we aim to review recent advances in how plants respond to heterogenous light cues and integrate these with other environmental signals."
Authors: Zengkang Zhai, Qianqian Ao, Liuqing Yang, Fangxiao Lu, Haokun Cheng, Qinxin Fang, Chun Li, Qinqin Chen, Jingli Yan, Yongsheng Wei, Yuan-Qing Jiang and Bo Yang.
Journal of Food and Agricultural Chemistry (2024)
Abstract: "Global water deficit is a severe abiotic stress threatening the yielding and quality of crops. Abscisic acid (ABA) is a phytohormone that mediates drought tolerance. Protein kinases and phosphatases function as molecular switches in eukaryotes. Protein phosphatases type 2C (PP2Cs) are a major family that play essential roles in ABA signaling and stress responses. However, the role and underlying mechanism of PP2C in rapeseed (Brassica napus L.) mediating drought response has not been reported yet. Here, we characterized a PP2C family member, BnaPP2C37, and its expression level was highly induced by ABA and dehydration treatments. It negatively regulates drought tolerance in rapeseed. We further identified that BnaPP2C37 interacted with multiple PYR/PYL receptors and a drought regulator BnaCPK5 (calcium-dependent protein kinase 5) through yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays. Specifically, BnaPYL1 and BnaPYL9 repress BnaPP2C37 phosphatase activity. Moreover, the pull-down assay and phosphatase assays show BnaPP2C37 interacts with BnaCPK5 to dephosphorylate BnaCPK5 and its downstream BnaABF3. Furthermore, a dual-luciferase assay revealed BnaPP2C37 transcript level was enhanced by BnaABF3 and BnaABF4, forming a negative feedback regulation to ABA response. In summary, we identified that BnaPP2C37 functions negatively in drought tolerance of rapeseed, and its phosphatase activity is repressed by BnaPYL1/9 whereas its transcriptional level is upregulated by BnaABF3/4."
Authors: Wentao Yang, Huawei Zhai, Fangming Wu, Lei Deng, Yu Chao, Xianwen Meng, Qian Chen, Chenhuan Liu, Xiaomin Bie, Chuanlong Sun, Yang Yu, Xiaofei Zhang, Xiaoyue Zhang, Zeqian Chang, Min Xue, Yajie Zhao, Xiangbing Meng, Boshu Li, Xiansheng Zhang, Dajian Zhang, Xiangyu Zhao, Caixia Gao, Jiayang Li and Chuanyou Li.
Cell (2024)
Editor's view: REF1 is a systemin-independent local wound signal that promotes regenerative responses, and the application of REF1 enhances the transformation efficiency of recalcitrant crops by boosting their regeneration capacity.
Highlights: • REF1 is a systemin-independent local wound signal promoting regenerative responses • REF1 is perceived by the receptor PORK1 for plant regeneration • REF1-PORK1 promotes regeneration via activating the master transcription factor WIND1 • REF1 offers a simple method to boost the regeneration efficiency of recalcitrant crops
Abstract: "Plants frequently encounter wounding and have evolved an extraordinary regenerative capacity to heal the wounds. However, the wound signal that triggers regenerative responses has not been identified. Here, through characterization of a tomato mutant defective in both wound-induced defense and regeneration, we demonstrate that in tomato, a plant elicitor peptide (Pep), REGENERATION FACTOR1 (REF1), acts as a systemin-independent local wound signal that primarily regulates local defense responses and regenerative responses in response to wounding. We further identified PEPR1/2 ORTHOLOG RECEPTOR-LIKE KINASE1 (PORK1) as the receptor perceiving REF1 signal for plant regeneration. REF1-PORK1-mediated signaling promotes regeneration via activating WOUND-INDUCED DEDIFFERENTIATION 1 (WIND1), a master regulator of wound-induced cellular reprogramming in plants. Thus, REF1-PORK1 signaling represents a conserved phytocytokine pathway to initiate, amplify, and stabilize a signaling cascade that orchestrates wound-triggered organ regeneration. Application of REF1 provides a simple method to boost the regeneration and transformation efficiency of recalcitrant crops.
Authors: Zhen Zhang, Cui Chen, Changyue Jiang, Hong Lin, Yuhui Zhao and Yinshan Guo.
Horticulture Research (2024)
Abstract: "Wounding stress induces the biosynthesis of various secondary metabolites in plants, including anthocyanin. However, the underlying molecular mechanism remains elusive. Here, we reported that a transcription factor, VvWRKY5, promotes wounding-induced anthocyanin accumulation in grape (Vitis vinifera). Biochemical and molecular analyses demonstrated that wounding stress significantly increased anthocyanin content, and VvMYBA1 plays an essential role in this process. VvWRKY5 could interact with VvMYBA1 and amplify the activation effect of VvMYBA1 on its target gene VvUFGT. The transcript level of VvWRKY5 was notably induced by wounding treatment. Moreover, our data demonstrated that VvWRKY5 could promote the synthesis of jasmonic acid (JA), a phytohormone that acts as a positive modulator in anthocyanin accumulation, by directly binding to the W-box element in the promoter of the JA biosynthesis-related gene VvLOX and enhancing its activities, and this activation was greatly enhanced by the VvWRKY5-VvMYBA1 protein complex. Collectively, our findings show that VvWRKY5 plays crucial roles in wounding-induced anthocyanin synthesis in grape and elucidates the transcriptional regulatory mechanism of wounding-induced anthocyanin accumulation."
Authors: Zilu Zhang, Qi Wang, Haiqiao Yan, Xiaoyan Cang, Wei Li, Jinyu He, Meixiang Zhang, Laiqing Lou, Ran Wang and Ming Chang.
New Crops (2024)
Abstract: "Calcium ions (Ca2+) serve as key messengers in plant immune reactions. A typical Ca2+ signaling involves three steps: encoding specific Ca2+ signatures by Ca2+-permeable channels, decoding Ca2+ signals by Ca2+ sensors, and downstream responses. This review focuses on plasma membrane-localized Ca2+-permeable channels and cytosolic Ca2+ sensors, unraveling their roles in cytosolic Ca2+ influx and immune signaling during pattern-triggered immunity, effector-triggered immunity, and autoimmunity. Several unresolved questions were highlighted, including the regulation of Ca2+-permeable channel activity for immune induction and the mechanism behind Ca2+ influx-triggered hypersensitive response cell death. This concise overview provides insights into the complex interplay of Ca2+ signaling in plant immunity, paving the way for future investigations on molecular plant-microbe interactions."
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Authors: Stephan Pollmann, Adrián González Ortega-Villaizán, Eoghan King, Manish K. Patel, Marta-Marina Pérez-Alonso, Sandra Scholz, Hitoshi Sakakibara, Takatoshi KIba, Mikiko Kojima, Yumiko Takebayashi, Patricio Ramos, Luis Morales-Quintana, Sarah Breitenbach, Ana Smolko, Branka Salopek-Sondi, Nataša Bauer, Jutta Ludwig-Müller, Anne Krapp, Ralf Oelmüller and Jesús Vicente-Carbajosa.
Authorea (2024)
Abstract: "Plants share their habitats with a multitude of different microbes. This close vicinity promoted the evolution of inter-organismic interactions between plants and many different microorganisms that provide mutual growth benefits both to the plant and the microbial partner. The symbiosis of Arabidopsis thaliana with the beneficial root colonizing endophyte Serendipita indica represents a well-studied system. Co-colonization of Arabidopsis roots with S. indica significantly promotes plant growth. Due to the notable phenotypic alterations of fungus-infected root systems, the involvement of a reprogramming of plant hormone levels, especially that of indole-3-acetic acid, has been suggested earlier. However, until now, the molecular mechanism by which S. indica promotes plant growth remains largely unknown. This study used comprehensive transcriptomics, metabolomics, reverse genetics, and life cell imaging to reveal the intricacies of auxin-related processes that affect root growth in the symbiosis between A. thaliana and S. indica. Our experiments revealed the essential role of tightly controlled auxin conjugation in the plant–fungus interaction. It particularly highlighted the importance of two GRETCHEN HAGEN 3 ( GH3) genes, GH3.5 and GH3.17, for the fungus infection-triggered stimulation of biomass production, thus broadening our knowledge about the function of GH3s in plants. Furthermore, we provide evidence for the transcriptional alteration of the PIN2 auxin transporter gene in roots of Arabidopsis seedlings infected with S. indica and demonstrate that this transcriptional adjustment affects auxin signaling in roots, which results in increased plant growth.
Authors: Aime Jaskolowski and Yves Poirier.
The Plant Journal (2024)
Significance Statement: When plants are subjected to a combination of biotic and abiotic stresses, the response to each individual stress is usually a poor predictor of the global response. Here, we show that when Arabidopsis plants are grown under phosphate deficiency, they increase the accumulation of the stress phytohormone abscisic acid, which in turn leads to higher susceptibility to infection by the necrotrophic fungus Botrytis cinerea, in part because of increased spore germination on the leaf surface.
Abstract: "Plants have evolved finely regulated defense systems to counter biotic and abiotic threats. In the natural environment, plants are typically challenged by simultaneous stresses and, amid such conditions, crosstalk between the activated signaling pathways becomes evident, ultimately altering the outcome of the defense response. As an example of combined biotic and abiotic stresses, inorganic phosphate (Pi) deficiency, common in natural and agricultural environments, can occur along with attack by the fungus Botrytis cinerea, a devastating necrotrophic generalist pathogen responsible for massive crop losses. We report that Pi deficiency in Arabidopsis thaliana increases its susceptibility to infection by B. cinerea by influencing the early stages of pathogen infection, namely spore adhesion and germination on the leaf surface. Remarkably, Pi-deficient plants are more susceptible to B. cinerea despite displaying the appropriate activation of the jasmonic acid and ethylene signaling pathways, as well as producing secondary defense metabolites and reactive oxygen species. Conversely, the callose deposition in response to B. cinerea infection is compromised under Pi-deficient conditions. The levels of abscisic acid (ABA) are increased in Pi-deficient plants, and the heightened susceptibility to B. cinerea observed under Pi deficiency can be reverted by blocking ABA biosynthesis. Furthermore, high level of leaf ABA induced by overexpression of NCED6 in Pi-sufficient plants also resulted in greater susceptibility to B. cinerea infection associated with increased spore adhesion and germination, and reduced callose deposition. Our findings reveal a link between the enhanced accumulation of ABA induced by Pi deficiency and an increased sensitivity to B. cinerea infection."
Authors: Zengqian Wang, Guiqing Yang, Dandan Zhang, Guangxin Li, Jin-Long Qiu and Jie Wu.
aBIOTECH (2024)
Abstract: "Salicylic acid (SA) is a phytohormone required for plant growth and defense signaling. There are two major SA biosynthesis pathways in plants: the isochorismate synthase (ICS) pathway and the phenylalanine ammonia-lyase (PAL) pathway. It has been demonstrated in several plant species, including the model plant Arabidopsis, that SA is derived predominantly from the ICS pathway. Here, we employed the CRISPR/Cas9 system to generate ICS knockout mutants in rice (Oryza sativa L.). The Osics mutants display severe growth defects, and are completely devoid of phylloquinone, an isochorismate-derived product. The growth defects of Osics can be rescued through exogenous application of 1,4-dihydroxy-2-naphthoic acid (NA), a precursor of phylloquinone. Remarkably, the basal SA levels are not altered in the Osics mutants. Our findings support a role of OsICS in the biosynthesis of phylloquinone, and imply that SA biosynthesis in rice may occur through an alternative route other than the ICS pathway."
Authors: Zhenghua He, Pei Zhang, Haitao Jia, Shilong Zhang, Elsayed Nishawy, Xiaopeng Sun and Mingqiu Dai.
New Crops (2024)
Abstract: "Drought is a primary abiotic stress affecting crops, leading to plant stomatal closure, reduced photosynthetic capacity, and reduced yields or even harvest failure. Severe drought can adversely impact agricultural production, ecosystems, and socio-economic capacities. Recently, researchers have studied the regulatory mechanisms of crop drought resistance and cloned hundreds of genes via genetic and molecular approaches. However, a limited number of the cloned genes have been successfully employed in drought resistance breeding, suggesting that drought resistance regulation is too complex. More work must be done to fully understand the regulatory networks of drought responses to breed drought-resistant and high-yield crop varieties. This review outlines the current achievements in investigating crop drought responses, particularly regulation by phytohormones and regulation of genes at transcriptional, post-translational, and epigenetic levels in crop drought responses. Finally, we examine the problems and potential solutions in breeding crop drought resistance and propose strategies for crop drought resistance improvement."
Authors: Tian Su, Ziwei Li, Yinghua Zhang, Junqiang Xu and Bin Xu.
Journal of the American Society for Horticultural Science (2024)
Abstract: "Cucumber (Cucumis sativus L.) belongs to the cucumber genus of the Cucurbitaceae family, and the selection of cultivars with minimal or no lateral branches can enhance the cultivation management efficiency. The growth of lateral branches is inhibited by strigolactone. To investigate the regulatory mechanism of strigolactone on the lateral branch development in cucumber, the cultivar LZ1 exhibiting multiple lateral branches was selected as the experimental material. The axillae of the plants were infiltrated with 1, 5, and 10 μmol·L−1 germination releaser 24 (GR24) at the four- to five-leaf stage. It was identified that 1 μmol·L−1 GR24 exhibited the most potent inhibitory effect on cucumber lateral branches. Additionally, exogenous strigolactone decreased the auxin content in the apical bud and axillae and increased the auxin content in the stem. This inhibited polar auxin transport in the axillary bud and promoted polar auxin transport in the apical bud. The content of strigolactone in the axilla region of cucumbers was elevated, whereas the synthesis and expression of cytokinin in the same area were reduced. A low concentration of GR24 induced the expression of cucumber branched 1 (csbrc1), whereas a high concentration of GR24 downregulated the expression of cucumber lateral suppressor (cscls) and blind (csblind), which inhibited the growth of cucumber lateral branches."
Authors: Nathalie Kuhn, Macarena Arellano, Claudio Ponce, Christian Hodar, Francisco Correa, Salvatore Multari, Stefan Martens, Esther Carrera, José Manuel Donoso and Lee A. Meisel
Journal of Plant Growth Regulation (2024)
Abstract: "Abscisic acid (ABA) is a plant hormone that plays a key role in the ripening process of non-climacteric fruits, triggering pigment production, fruit softening, and sugar accumulation. Transcriptional studies show that ABA modifies the expression of several ripening-related genes, but epigenetic effects of ABA during this process are lacking. Therefore, this work aimed to perform transcriptomic and DNA methylation analyses of fruit samples treated with ABA during the fruit ripening process in the non-climacteric sweet cherry model. RNA-seq analyses revealed an overrepresentation of transcripts annotated in functional categories related to ABA response, secondary metabolism, and sugar synthesis during fruit ripening. In contrast, Whole Genome Bisulfite Sequencing (WGBS) analyses revealed DNA hypomethylation in the 5′UTR region of genes related to carotene catabolism. Transcriptional and epigenetic regulation of genes encoding xyloglucan enzymes, associated with cell wall modifications, were also detected. ABA treatment enhanced fruit color development and the accumulation of ripening markers, including carotenoids and several anthocyanins. Gene Ontology analysis in the RNA-seq of ABA-treated fruits revealed expression variations in genes encoding members of the Aux/IAA and ARF families. In the WGBS analysis, genes encoding enzymes for cytokinin biosynthesis had differential DNA methylation after the ABA treatment. Our work identified ABA-modulated factors at the genetic and epigenetic levels, suggesting complex hormone networks controlling non-climacteric sweet cherry fruit ripening."
Authors: Dachuan Gu, Shuhua Wu, Yuxin Wang, Yuhua Yang, Jiaming Chen, Kaiquan Mao, Yinyin Liao, Jianlong Li, Lanting Zeng and Ziyin Yang.
Plant, Cell & Environment (2024)
Summary statement: Tea green leafhopper infestations affect tea plant growth by altering the synthesis of brassinolide. The results of this study broaden our understanding of the brassinolide response induced by insect-related biotic stress in horticultural crops.
Abstract: "Tea green leafhoppers are insects widely distributed in major tea-growing areas. At present, less attention has been paid to the study on effect of tea green leafhopper infestation on tea growth phenotype. In this study, tea green leafhoppers were used to treat tea branches in laboratory and co-treated with brassinolide (BL), the highest bioactivity of brassinosteroids (BRs), in tea garden. The results showed that the expression of genes related to BRs synthesis was inhibited and BL content was reduced in tea shoots after infestation by tea green leafhoppers. In addition, area of each leaf position, length and diameter of internodes, and the biomass of the tender shoots of tea plant were decreased after infestation by tea green leafhoppers. The number of trichomes, leaf thickness, palisade tissue thickness and cuticle thickness of tea shoots were increased after tea green leafhoppers infestation. BL spraying could partially recover the phenotypic changes of tea branches caused by tea green leafhoppers infestation. Further studies showed that tea green leafhoppers infestation may regulate the expression of CsDWF4 (a key gene for BL synthesis) through transcription factors CsFP1 and CsTCP1a, which finally affect the BL content. Moreover, BL was applied to inhibit the tea green leafhoppers infestation on tea shoots. In conclusion, our study revealed the effect of plant hormone BL-mediated tea green leafhoppers infestation on the growth phenotype of tea plants."
Authors: Jaroslav Nisler, Pavel Klimeš, Radka Končitíková, Alena Kadlecová, Jiří Voller, Mahfam Chalaki, Michael Karampelias, Nino Murvanidze, Stefaan P O Werbrouck, David Kopečný, Libor Havlíček, Nuria de Diego, Pierre Briozzo, Solange Moréra, David Zalabák and Lukáš Spíchal.
Journal of Experimental Botany (2024)
Abstract: "Cytokinin oxidase/dehydrogenase (CKX) inhibitors reduce the degradation of cytokinins in plants and thereby may improve the efficiency of agriculture and plant tissue culture-based practices. Here, we report a synthesis and structure-activity relationship study of novel urea derivatives concerning their CKX inhibitory activity. The best compounds showed sub-nanomolar IC50 values with maize ZmCKX1, the lowest value yet documented. Other CKX isoforms of maize (Zea mays) and Arabidopsis were also inhibited very effectively. The binding mode of four compounds was characterized based on high-resolution crystal complex structures. Using the soil nematode Caenorhabditis elegans, and human skin fibroblasts, key CKX inhibitors with low toxicity were identified. These compounds enhanced the shoot regeneration of Lobelia, Drosera, and Plectranthus, as well as the growth of Arabidopsis and Brassica napus. At the same time, a key compound (namely 82), activated a cytokinin primary response gene ARR5:GUS and cytokinin sensor TCSv2:GUS, without activating the Arabidopsis cytokinin receptors AHK3 and AHK4. This strongly implies that the effect of compound 82 is due to the upregulation of cytokinin signalling. Overall, this work presents highly effective and easily prepared CKX inhibitors with a low risk of environmental toxicity for further investigation of their potential in agriculture and biotechnology."
Authors: Shotaro Hirota, Yusuke Ito, Shiro Inoue, Naoki Kitaoka, Tohru Taniguchi, Kenji Monde, Kosaku Takahashi and Hideyuki Matsuura.
Journal of Natural Products (2024)
Abstract: "cis-12-oxo-Phytodieneoic acid-α-monoglyceride (1) was isolated from Arabidopsis thaliana. The chemical structure of 1 was elucidated based on exhaustive 1D and 2D NMR spectroscopic measurements and supported by FDMS and HRFDMS data. The absolute configuration of the cis-OPDA moiety in 1 was determined by comparison of 1H NMR spectra and ECD measurements. With respect to the absolute configuration of the β-position of the glycerol backbone, the 2:3 ratio of (S) to (R) was determined by making ester-bonded derivatives with (R)-(+)-α-methoxy-α-trifluoromethylphenylacetyl chloride and comparing 1H NMR spectra. Wounding stress did not increase endogenous levels of 1, and it was revealed 1 had an inhibitory effect of A. thaliana post germination growth. Notably, the endogenous amount of 1 was higher than the amounts of (+)-7-iso-jasmonic acid and (+)-cis-OPDA in intact plants. 1 also showed antimicrobial activity against Gram-positive bacteria, but jasmonic acid did not. It was also found that α-linolenic acid-α-monoglyceride was converted into 1 in the A. thaliana plant, which implied α-linolenic acid-α-monoglyceride was a biosynthetic intermediate of 1."
Authors: Craig L. Cowling, Arielle L. Homayouni, Jodi B. Callwood , Maxwell R. McReynolds, Jasper Khor, Haiyan Ke, Melissa A. Draves, Katayoon Dehesh, Justin W. Walley, Lucia C. Strader and Dior R. Kelley.
PNAS (2024)
Significance: Roots are a key organ for water and nutrient uptake in plants. Changes in root architecture can impact yield and resilience to stress in crops. To find factors that contribute to root development in corn, a genetic screen was performed. Herein, we identify a hormone transporter that influences numerous root traits of agronomic significance. This work has implications for translational approaches aimed at improving cereal crops.
Abstract: "Plant root systems play a pivotal role in plant physiology and exhibit diverse phenotypic traits. Understanding the genetic mechanisms governing root growth and development in model plants like maize is crucial for enhancing crop resilience to drought and nutrient limitations. This study focused on identifying and characterizing ZmPILS6, an annotated auxin efflux carrier, as a key regulator of various crown root traits in maize. ZmPILS6-modified roots displayed reduced network area and suppressed lateral root formation, which are desirable traits for the “steep, cheap, and deep” ideotype. The research revealed that ZmPILS6 localizes to the endoplasmic reticulum and plays a vital role in controlling the spatial distribution of indole-3-acetic acid (IAA or “auxin”) in primary roots. The study also demonstrated that ZmPILS6 can actively efflux IAA when expressed in yeast. Furthermore, the loss of ZmPILS6 resulted in significant proteome remodeling in maize roots, particularly affecting hormone signaling pathways. To identify potential interacting partners of ZmPILS6, a weighted gene coexpression analysis was performed. Altogether, this research contributes to the growing knowledge of essential genetic determinants governing maize root morphogenesis, which is crucial for guiding agricultural improvement strategies."
Authors: Yidong Wang, Lanlan Jiang, Dongdong Kong, Jie Meng, Meifang Song, Wenxiu Cui, Yaqi Song, Xiaofan Wang, Jiao Liu, Rui Wang, Yikun He, Caren Chang and Chuanli Ju.
New Phytologist (2024)
Abstract: "The conquest of land by plants was concomitant with, and possibly enabled by, the evolution of three-dimensional (3D) growth. The moss Physcomitrium patens provides a model system for elucidating molecular mechanisms in the initiation of 3D growth. Here, we investigate whether the phytohormone ethylene, which is believed to have been a signal before land plant emergence, plays a role in 3D growth regulation in P. patens. We report ethylene controls 3D gametophore formation, based on results from exogenously applied ethylene and genetic manipulation of PpEIN2, which is a central component in the ethylene signaling pathway. Overexpression (OE) of PpEIN2 activates ethylene responses and leads to earlier formation of gametophores with fewer gametophores produced thereafter, phenocopying ethylene-treated wild-type. Conversely, Ppein2 knockout mutants, which are ethylene insensitive, show initially delayed gametophore formation with more gametophores produced later. Furthermore, pharmacological and biochemical analyses reveal auxin levels are decreased in the OE lines but increased in the knockout mutants. Our results suggest that evolutionarily, ethylene and auxin molecular networks were recruited to build the plant body plan in ancestral land plants. This might have played a role in enabling ancient plants to acclimate to the continental surfaces of the planet."
Authors: Songyu Pei, Qi Tao, Wenke Li, Guoning Qi, Borong Wang, Yan Wang, Shiwen Dai, Qiujing Shen, Xi Wang, Xiaomei Wu, Shijian Xu, Lynn Theprungsirikul, Jingyuan Zhang, Liang Liang, Yuantao Liu, Kena Chen, Yang Shen, Bridget M. Crawford, Mengjia Cheng, Qi Zhang, Yiqi Wang, Hongli Liu, Benguang Yang, Bryan Krichilsky, Jessica Pei, Karen Song, Douglas M. Johnson, Zhonghao Jiang, Feihua Wu, Gary B. Swift, Huanghe Yang, Zhonghua Liu, Xuexiao Zou, Tuan Vo-Dinh, Feng Liu, Zhen-Ming Pei and Fang Yuan.
Nature (2024)
One-sentence summary: Screening in Escherichia coli and biochemical experiments show that in Arabidopsis thaliana, OSCA2.1 and OSCA2.2 function as plant sensors of hypo-osmolarity, utilize Ca2+ oscillations as second messengers and have crucial roles in pollen germination.
Abstract: "Higher plants survive terrestrial water deficiency and fluctuation by arresting cellular activities (dehydration) and resuscitating processes (rehydration). However, how plants monitor water availability during rehydration is unknown. Although increases in hypo-osmolarity-induced cytosolic Ca2+ concentration (HOSCA) have long been postulated to be the mechanism for sensing hypo-osmolarity in rehydration1,2, the molecular basis remains unknown. Because osmolarity triggers membrane tension and the osmosensing specificity of osmosensing channels can only be determined in vivo3,4,5, these channels have been classified as a subtype of mechanosensors. Here we identify bona fide cell surface hypo-osmosensors in Arabidopsis and find that pollen Ca2+ spiking is controlled directly by water through these hypo-osmosensors—that is, Ca2+ spiking is the second messenger for water status. We developed a functional expression screen in Escherichia coli for hypo-osmosensitive channels and identified OSCA2.1, a member of the hyperosmolarity-gated calcium-permeable channel (OSCA) family of proteins6. We screened single and high-order OSCA mutants, and observed that the osca2.1/osca2.2 double-knockout mutant was impaired in pollen germination and HOSCA. OSCA2.1 and OSCA2.2 function as hypo-osmosensitive Ca2+-permeable channels in planta and in HEK293 cells. Decreasing osmolarity of the medium enhanced pollen Ca2+ oscillations, which were mediated by OSCA2.1 and OSCA2.2 and required for germination. OSCA2.1 and OSCA2.2 convert extracellular water status into Ca2+ spiking in pollen and may serve as essential hypo-osmosensors for tracking rehydration in plants."
Authors: Malathi Bheri, Amit Kumar and Girdhar K. Pandey.
Trends in Plant Science (2024)
Abstract: "Potassium (K) is an essential macronutrient for plant development. Although the low-K+-responsive calcium (Ca2+) signaling pathway is known, its regulator remained elusive. Li et al. recently demonstrated that the target of rapamycin complex (TORC) and Ca2+ signaling pathways show reciprocal regulation of K+-responsive growth in plants."
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