
Salt stress disrupts the coordination between root and shoot growth in Arabidopsis, and the gene SR3G acts as a negative regulator of root suberization, shoot growth, and sodium accumulation, thereby reducing plant salt resilience.


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Soil salinity is one of the major threats to agricultural productivity worldwide. Salt stress exposure alters root and shoot growth rates, thereby affecting overall plant performance. While past studies have extensively documented the effect of salt stress on root elongation and shoot development separately, here we take an innovative approach by examining the coordination of root and shoot growth under salt stress conditions. Utilizing a newly developed tool for quantifying the root:shoot ratio in agar-grown Arabidopsis seedlings, we found that salt stress results in a loss of coordination between root and shoot growth rates. We identify a specific gene cluster encoding domain-of-unknown-function 247 (DUF247), and characterize one of these genes as Salt Root:shoot Ratio Regulator Gene (SR3G). Further analysis elucidates the role of SR3G as a negative regulator of salt stress tolerance, revealing its function in regulating shoot growth, root suberization, and sodium accumulation. We further characterize that SR3G expression is modulated by WRKY75 transcription factor, known as a positive regulator of salt stress tolerance. Finally, we show that the salt stress sensitivity of wrky75 mutant is completely diminished when it is combined with sr3g mutation. Together, our results demonstrate that utilizing root:shoot ratio as an architectural feature leads to the discovery of new stress resilience gene. The study’s innovative approach and findings not only contribute to our understanding of plant stress tolerance mechanisms but also open new avenues for genetic and agronomic strategies to enhance crop environmental resilience.

### Competing Interest Statement

The authors have declared no competing interest.

Natural variation in salt-induced changes in root:shoot ratio reveals SR3G as a negative regulator of root suberization and salt resilience in Arabidopsis

salt-stress-disrupts-coordination-between-root-and-shoot-growth-in-arabidopsis-revealing-sr3g-as-a-negative-regulator-of-root-suberization-and-salt-resilience


Salt Stress Disrupts Coordination Between Root and Shoot Growth in Arabidopsis, Revealing SR3G as a Negative Regulator of Root Suberization and Salt Resilience


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Plants possess sophisticated mechanisms to sense and respond to gravity, which are crucial for their growth, development, and adaptation.


LAZY proteins hitchhike when roots reorient relative to gravity.

Things fall into place: how plants sense and respond to gravity

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Gravity Sensing and Response Mechanisms in Plants: Insights into Growth and Evolution



TWA1 is a temperature-sensing transcriptional co-regulator that is essential for basal and acquired thermotolerance in Arabidopsis thaliana.


TWA1 is a temperature-sensing transcriptional co-regulator that is needed for basal and acquired thermotolerance in Arabidopsis thaliana.

The temperature sensor TWA1 is required for thermotolerance in Arabidopsis - Nature

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Identification of the Temperature Sensor TWA1 Required for Thermotolerance in Arabidopsis



Elevated CO2 leads to a global decrease in the mineral composition of Arabidopsis thaliana plants, but natural genetic variation allows for a wide range of responses, from negative to positive effects.


The elevation of atmospheric CO2 leads to a decline in the plant mineral content, which might pose a significant threat to food security in the coming decades. To date, very few genes have been identified as having a role in the negative effect of elevated CO2 on plant mineral composition. Yet, several studies have shown a certain degree of diversity in the ionome’s response to elevated CO2, associated with genotypic variation. This suggests the existence of genetic factors controlling the effect of CO2 on ionome composition. However, no large-scale studies have been carried out to date to explore the genetic diversity of the ionome responses to elevated CO2. Here, we used six hundred Arabidopsis thaliana accessions, representing geographical distributions ranging from worldwide to regional and local environments, to analyze the natural genetic variation underlying the negative effect of elevated CO2 on the ionome composition in plants. We show that the growth under elevated CO2 leads to a global and important decrease of the ionome content whatever the geographic distribution of the population. We also observed a high range of genetic diversity in the response of the ionome composition to elevated CO2, and we identified sub-populations, showing effects on their ionome ranging from the most pronounced to resilience or even to a benefit in response to elevated CO2. Using genome-wide association mapping on the response of each mineral element to elevated CO2 or on integrative traits, we identified a large set of QTLs and genes associated with the ionome response to elevated CO2. Finally, we demonstrate that the function of one of these genes is associated to the negative effect of elevated CO2 on the plant mineral composition. This resource will contribute to understand the genetic mechanisms underlying the negative effect of elevated CO2 on plant mineral nutrition, and could help towards the development of crops adapted to a high-CO2 world.

### Competing Interest Statement

The authors have declared no competing interest.

Natural genetic variation underlying the negative effect of elevated CO2 on ionome composition in Arabidopsis thaliana

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Genetic Variation Underlying the Negative Effect of Elevated CO2 on Mineral Composition in Arabidopsis thaliana



Pectin demethylation status is a key determinant for the perception and signaling output of the plant peptide hormone RALF1 via the receptor FERONIA.


The extracellular matrix plays an integrative role in cellular responses in plants, but its contribution to the signalling of extracellular ligands largely remains to be explored. RAPID ALKALINIZATION FACTORs (RALFs) are extracellular peptide hormones that play pivotal roles in various physiological processes. Here, we address a crucial connection between the demethylation machinery of the cell wall component pectin and RALF1 activity. Pectin is a polysaccharide, contributing to the structural integrity of the cell wall. Our data illustrate that the pharmacological and genetic interference with PECTIN METHYL ESTERASEs (PMEs) abolishes RALF1-induced root growth repression. Our data suggest that positively charged RALF1 peptides bind negatively charged, demethylated pectin with high avidity. We illustrate that the RALF1 association with demethylated pectin is required for its FERONIA-dependent perception, contributing to the control of the extracellular matrix and the regulation of plasma membrane dynamics. Notably, this mode of action is independent of the FER-dependent extracellular matrix sensing mechanism provided by FER interaction with the Leucine-Rich Repeat Extensin (LRX) proteins. We propose that the methylation status of pectin acts as a conceptualizing signalling scaffold for RALF peptides, linking extracellular matrix dynamics to peptide hormone-mediated responses.

### Competing Interest Statement

The authors have declared no competing interest.

Pectin methylesterase activity is required for RALF1 peptide signalling output

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Pectin Methylesterase Activity is Crucial for RALF1 Peptide Signaling in Plant Roots



The IDA peptide signaling pathway regulates both developmental cell separation processes and immune responses in Arabidopsis, ensuring optimal protection of cells undergoing separation that are vulnerable to pathogen attack.


The abscission of floral organs and emergence of lateral roots in Arabidopsis is regulated by the peptide ligand INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) and the receptor protein kinases HAESA (HAE) and HAESA-LIKE 2 (HSL2). During these cell separation processes, the plant induces defense-associated genes to protect against pathogen invasion. However, the molecular coordination between abscission and immunity has not been thoroughly explored. Here we show that IDA induces a release of cytosolic calcium ions (Ca2+) and apoplastic production of reactive oxygen species, which are signatures of early defense responses. In addition, we find that IDA promotes late defense responses by the transcriptional upregulation of genes known to be involved in immunity. When comparing the IDA induced early immune responses to known immune responses, such as those elicited by flagellin22 treatment, we observe both similarities and differences. We propose a molecular mechanism by which IDA promotes signatures of an immune response in cells destined for separation to guard them from pathogen attack.

### Competing Interest Statement

The authors have declared no competing interest.

A dual function of the IDA peptide in regulating cell separation and modulating plant immunity at the molecular level

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INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) Peptide Signaling Coordinates Cell Separation and Immune Responses in Arabidopsis



OsNF-YB7 acts as a transcriptional repressor to inhibit chlorophyll biosynthesis in rice embryo by interacting with OsGLK1.


As a master regulator of seed development, Leafy Cotyledon 1 (LEC1) promotes chlorophyll (Chl) biosynthesis in Arabidopsis , but the mechanism underlying this remains poorly understood. Here, we found that loss of function of OsNF-YB7 , a LEC1 homolog of rice, leads to chlorophyllous embryo, indicating that OsNF-YB7 plays an opposite role in Chl biosynthesis in rice compared with that in Arabidopsis . OsNF-YB7 regulates the expression of a group of genes responsible for Chl biosynthesis and photosynthesis by directly binding to their promoters. In addition, OsNF-YB7 interacts with Golden 2-Like 1 (OsGLK1) to inhibit the transactivation activity of OsGLK1, a key regulator of Chl biosynthesis. Moreover, OsNF-YB7 can directly repress OsGLK1 expression by recognizing its promoter in vivo , indicating the involvement of OsNF-YB7 in multiple regulatory layers of Chl biosynthesis in rice embryo. We propose that OsNF-YB7 functions as a transcriptional repressor to regulate Chl biosynthesis in rice embryo.

### Competing Interest Statement

The authors have declared no competing interest.

OsNF-YB7 inactivates OsGLK1 to inhibit chlorophyll biosynthesis in rice embryo

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OsNF-YB7 Role in Inhibiting Chlorophyll Biosynthesis in Rice Embryo



TRAPPII phosphostatus influences adaptive responses to stress cues.


Plants often adapt to adverse or stress conditions via differential growth. The trans-Golgi Network (TGN) has been implicated in stress responses, but it is not clear in what capacity it mediates adaptive growth decisions. In this study, we assess the role of the TGN in stress responses by exploring the interactome of the Transport Protein Particle II (TRAPPII) complex, required for TGN structure and function. We identified physical and genetic interactions between TRAPPII and shaggy-like kinases (GSK3/AtSKs). Kinase assays and pharmacological inhibition provided in vitro and in vivo evidence that AtSKs target the TRAPPII-specific subunit AtTRS120/TRAPPC9. GSK3/AtSK phosphorylation sites in AtTRS120/TRAPPC9 were mutated, and the resulting AtTRS120 phosphovariants subjected to a variety of single and multiple stress conditions in planta . The non-phosphorylatable TRS120 mutant exhibited enhanced adaptation to multiple stress conditions and to osmotic stress whereas the phosphomimetic version was less resilient. Higher order inducible trappii atsk mutants had a synthetically enhanced defect in root gravitropism. Our results suggest that the TRAPPII phosphostatus mediates adaptive responses to abiotic cues. AtSKs are multifunctional kinases that integrate a broad range of signals. Similarly, the TRAPPII interactome is vast and considerably enriched in signaling components. An AtSK-TRAPPII interaction would integrate all levels of cellular organization and instruct the TGN, a central and highly discriminate cellular hub, as to how to mobilize and allocate resources to optimize growth and survival under limiting or adverse conditions.

### Competing Interest Statement

The authors have declared no competing interest.

Regulation of adaptive growth decisions via phosphorylation of the TRAPPII complex in Arabidopsis

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Regulation of Adaptive Growth Decisions via TRAPPII Phosphorylation in Arabidopsis



Identification of BCP1-4 as functional counterparts of MDC1 in plant DDR.


Induction of DNA damage triggers rapid phosphorylation of the histone H2A.X (γH2A.X). In animals, mediator of DNA damage checkpoint 1 (MDC1) binds γH2A.X through a tandem BRCA1 carboxyl-terminal (tBRCT) domain and mediates recruitment of downstream effectors of DNA damage response (DDR). However, readers of this modification in plants have remained elusive. We report that from Arabidopsis BRCT domain proteome, BCP1-4 proteins with tBRCT domains are involved in DDR. Through its tBRCT domain BCP4 binds γH2A.X in vitro and localizes to DNA damage-induced foci in an H2A.X dependent manner. BCP4 also contains a domain that interacts directly with NBS1 and thus acts as a functional counterpart of MDC1. We also show that BCP1, that contains two tBRCT domains, co-localizes with γH2A.X but it does not bind γH2A.X suggesting functional similarity with human PAXIP1. A phylogenetic analysis supports that PAXIP1 and MDC1 in metazoa and their plant counterparts evolved independently from common ancestors with tBRCT domains. Collectively, our study reveals missing components and provides mechanistic and evolutionary insights into plant DDR.

### Competing Interest Statement

The authors have declared no competing interest.

This study includes no data deposited in external repositories.

Identification of plants functional counterparts of the metazoan Mediator of DNA Damage Checkpoint 1

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Co-evolution of functional motifs and H2A.X in plant DDR



The author explores how elevated temperatures affect centromere structure and chromosome segregation during meiosis in Arabidopsis, leading to reduced fertility. The study reveals that heat stress impacts the efficiency of kinetochore attachments to spindle microtubules, highlighting a critical bottleneck in plant adaptation to rising temperatures.


Heat stress is a major threat to global crop production, and understanding its impact on plant fertility is crucial for developing climate-resilient crops. Despite the known negative effects of heat stress on plant reproduction, the underlying molecular mechanisms remain poorly understood. Here, we investigated the impact of elevated temperature on centromere structure and chromosome segregation during meiosis in Arabidopsis thaliana . Consistent with previous studies, heat stress leads to a decline in fertility and micronuclei formation in pollen mother cells. Our results reveal that elevated temperature causes a decrease in the amount of centromeric histone and the kinetochore protein BMF1 at meiotic centromeres with increasing temperature. Furthermore, we show that heat stress increases the duration of meiotic divisions and prolongs the activity of the spindle assembly checkpoint during meiosis I, indicating an impaired efficiency of the kinetochore attachments to spindle microtubules. Our analysis of mutants with reduced levels of centromeric histone suggests that weakened centromeres sensitize plants to elevated temperature, resulting in meiotic defects and reduced fertility even at moderate temperatures. These results indicate that the structure and functionality of meiotic centromeres in Arabidopsis are highly sensitive to heat stress, and suggest that centromeres and kinetochores may represent a critical bottleneck in plant adaptation to increasing temperatures.

### Competing Interest Statement

The authors have declared no competing interest.

Heat stress impairs centromere structure and segregation of meiotic chromosomes in Arabidopsis

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Impact of Heat Stress on Meiotic Chromosomes in Arabidopsis
