ALDH18A1

NAC transcription factors are commonly involved in the plant response to drought stress. A transcriptome analysis of root samples of the soybean variety 'Jiyu47' under drought stress revealed the evidently up-regulated expression of GmNAC19, consistent with the expression pattern revealed by quantitative real-time PCR analysis. The overexpression of GmNAC19 enhanced drought tolerance in Saccharomyces cerevisiae INVSc1. The seed germination percentage and root growth of transgenic Arabidopsis thaliana were improved in comparison with those of the wild type, while the transgenic soybean composite line showed improved chlorophyll content. The altered contents of physiological and biochemical indices (i.e., soluble protein, soluble sugar, proline, and malondialdehyde) related to drought stress and the activities of three antioxidant enzymes (i.e., superoxide dismutase, peroxidase, and catalase) revealed enhanced drought tolerance in both transgenic Arabidopsis and soybean. The expressions of three genes (i.e., P5CS, OAT, and P5CR) involved in proline synthesis were decreased in the transgenic soybean hairy roots, while the expression of ProDH involved in the breakdown of proline was increased. This study revealed the molecular mechanisms underlying drought tolerance enhanced by GmNAC19 via regulation of the contents of soluble protein and soluble sugar and the activities of antioxidant enzymes, providing a candidate gene for the molecular breeding of drought-tolerant crop plants.

N⁶-methyladenosine (m⁶A) RNA modification is critical for plant growth, development, and environmental stress response. While short-term stress impacts on m⁶A are well-documented, the consequences of prolonged stress remain underexplored. This study conducts a thorough transcriptome-wide analysis of m⁶A modifications following 28-day exposure to 200mM NaCl. We detected 11,149 differentially expressed genes (DEGs) and 12,936 differentially methylated m⁶A peaks, along with a global decrease in m⁶A levels. Notably, about 62% of m⁶A-modified DEGs, including demethylase genes like PvALKBH6_N, PvALKBH9_K, and PvALKBH10_N, showed increased expression and reduced m⁶A peaks, suggesting that decreased m⁶A methylation may enhance gene expression under salt stress. Consistent expression and methylation patterns were observed in key genes related to ion homeostasis (e.g., H⁺-ATPase 1, High-affinity K⁺transporter 5), antioxidant defense (Catalase 1/2, Copper/zinc superoxide dismutase 2, Glutathione synthetase 1), and osmotic regulation (delta 1-pyrroline-5-carboxylate synthase 2, Pyrroline-5-carboxylate reductase). These findings provide insights into the adaptive mechanisms of switchgrass under long-term salt stress and highlight the potential of regulating m⁶A modifications as a novel approach for crop breeding strategies focused on stress resistance.

The cellular compartmentation induced by self-assembly of natural proteins has recently attracted widespread attention due to its structural-functional significance. Among them, as a highly conserved metabolic enzyme and one of the potential targets for cancers and parasitic diseases in drug development, CTP synthase (CTPS) has also been reported to self-assemble into filamentous structures termed cytoophidia. To elucidate the dynamical mechanism of cytoophidium filamentation, we utilize single-molecule fluorescence imaging to observe the real-time self-assembly dynamics of CTPS and the coordinated assembly between CTPS and its interaction partner, Δ¹-pyrroline-5-carboxylate synthase (P5CS). Significant differences exist in the direction of growth and extension when the two proteins self-assemble. The oligomer state distribution analysis of the CTPS minimum structural subunit under different conditions and the stoichiometry statistics of binding CTPS and P5CS by single-molecule fluorescence photobleach counting further confirm that the CTPS cytoophidia are mainly stacked with tetramers. CTPS can act as the nucleation core to induce the subsequent growth of the P5CS filaments. Our work not only provide evidence from the molecular level for the self-assembly and coordinated assembly (coassembly) of CTPS with its interaction partner P5CS in vitro but also offer new experimental perspectives for the dynamics research of coordinated regulation between other protein polymers.