Plant Physiology最新文献

The SWI/SNF (SWItch/Sucrose Non-Fermentable) chromatin remodeling complex is involved in various aspects of plant development and stress responses. Here, we investigated the role of BRM (BRAHMA), a core catalytic subunit of the SWI/SNF complex, in Arabidopsis thaliana seed biology. brm-3 seeds exhibited enlarged size, reduced yield, increased longevity, and enhanced secondary dormancy, but did not show changes in primary dormancy or salt tolerance. Some of these phenotypes depended on the expression of DOG1, a key regulator of seed dormancy, as they were restored in the brm-3 dog1-4 double mutant. Transcriptomic and metabolomic analyses revealed that BRM and DOG1 synergistically modulate the expression of numerous genes. Some of the changes observed in the brm-3 mutant, including increased glutathione levels, depended on a functional DOG1. We demonstrated that the BRM-containing chromatin remodeling complex directly controls secondary dormancy through DOG1 by binding and remodeling its 3' region, where the promoter of the long noncoding RNA asDOG1 is located. Our results suggest that BRM and DOG1 cooperate to control seed physiological properties and that BRM regulates DOG1 expression through asDOG1. This study reveals chromatin remodeling at the DOG1 locus as a molecular mechanism controlling the interplay between seed viability and dormancy.

Potato (Solanum tuberosum L.) is one of the most important food crops globally and is especially vulnerable to heat stress. However, substantial knowledge gaps remain in our understanding of the developmental mechanisms associated with tuber responses to heat stress. This study used whole-plant physiology, transcriptomics, and phytohormone profiling to elucidate how heat stress affects potato tuber development. When plants were grown in projected future elevated temperature conditions, abscisic acid (ABA) levels decreased in leaf and tuber tissues, whereas rates of leaf carbon assimilation and stomatal conductance were not significantly affected compared to those plants grown in historical temperature conditions. While plants grown in projected future elevated temperature conditions initiated more tubers per plant on average, there was a 66% decrease in mature tubers at the final harvest compared to those plants grown in historical temperature conditions. We hypothesize that reduced tuber yields at elevated temperatures are not due to reduced tuber initiation, but due to impaired tuber filling. Transcriptomic analysis detected significant changes in the expression of genes related to ABA response, heat stress, and starch biosynthesis. The tuberization repressor genes SELF-PRUNING 5G (StSP5G) and CONSTANS-LIKE1 (StCOL1) were differentially expressed in tubers grown in elevated temperatures. Two additional known tuberization genes, IDENTITY OF TUBER 1 (StIT1) and TIMING OF CAB EXPRESSION 1 (StTOC1), displayed distinct expression patterns under elevated temperatures compared to historical temperature conditions but were not differentially expressed. This work highlights potential gene targets and key developmental stages associated with tuberization to develop potatoes with greater heat tolerance.

Soil salinization threatens global crop production. Here, we report that a receptor-like cytoplasmic kinase, CALMODULIN-BINDING RECEPTOR-LIKE CYTOPLASMIC KINASE 3 (CRCK3), plays an essential role in plant salt tolerance via CATALASE 2 (CAT2), a hydrogen peroxide (H2O2)-scavenging enzyme in Arabidopsis (Arabidopsis thaliana). CRCK3 was induced by salt stress, and its knockout mutant displayed a salt-sensitive phenotype compared with wild-type plants. CRCK3 was activated by salt stress in a calcium-dependent manner, and its kinase activity was required for plant salt tolerance. CRCK3 physically interacted with CAT2, and CRCK3-mediated salt tolerance depended on CAT2. Salt treatment significantly induced CAT2 phosphorylation via the action of CRCK3, and this phosphorylation was required for CAT2-mediated H2O2 scavenging to reduce reactive oxygen species (ROS) content and oxidative damage in plants under saline conditions. CRCK3 phosphorylated CAT2 at the Thr209 residue, resulting in elevated catalase activity to reduce ROS accumulation under saline conditions. Therefore, the CRCK3-CAT2 module mediates plant salt tolerance by maintaining redox homeostasis. This study expands our knowledge of how plants respond to salt stress.