Discovery of 2,6-Dihalopurines as Stomata Opening Inhibitors: Implication of an LRX-Mediated H+-ATPase Phosphorylation Pathway

Chemical application improves stress resilience in plants

In recent years, abiotic stresses, including droughts, floods, high temperatures, and salinity, have become increasingly frequent and severe. These stresses significantly hinder crop yields and product quality, posing substantial challenges to sustainable agriculture and global food security. Simultaneously, the rapidly growing global population exacerbates the need to enhance crop production under worsening environmental conditions. Consequently, the development of effective strategies to strengthen the resilience of crop plants against high temperatures, water scarcity, and extreme environmental conditions is critical for mitigating the impacts of abiotic stress. Plants respond to these environmental challenges by reprogramming their transcriptome and metabolome. Common strategies for developing stress-tolerant plants include screening germplasm, generating transgenic crop plants, and employing genome editing techniques. Recently, chemical treatment has emerged as a promising approach to enhance abiotic stress tolerance in crops. This technique involves the application of exogenous chemical compounds that induce molecular and physiological changes, thereby providing a protective shield against abiotic stress. Forward and reverse genetic approaches have facilitated the identification of chemicals capable of modulating plant responses to abiotic stresses. These priming agents function as epigenetic regulators, agonists, or antagonists, playing essential roles in regulating stomatal closure to conserve water, managing cellular signaling through reactive oxygen species and metabolites to sustain plant growth, and activating gluconeogenesis to enhance cellular metabolism. This review summarizes recent advancements in the field of chemical priming and explores strategies to improve stress tolerance and crop productivity, thereby contributing to the enhancement of global food security.

Small chemical molecules regulating the phytohormone signalling alter the plant's physiological processes to improve stress adaptation, growth and productivity

Small chemical molecules are attractive agents for improving the plant processes associated with plant growth and stress tolerance. Recent advances in chemical biology and structure-assisted drug discovery approaches have opened up new avenues in plant biology to discover new drug-like molecules to improve plant processes for sustained food production. Several compounds targeting phytohormone biosynthesis or signalling cascades were designed to alter plant physiological mechanisms. Altering Abscisic acid synthesis and its signalling process can improve drought tolerance, and the processes targeted are reversible. Molecules targeting cytokinin, Auxin, and gibberellic acid regulate plant physiological processes and can potentially improve plant growth, biomass and productivity. The potential of molecules may be exploited as agrochemicals to enhance agricultural productivity. The discovery of small molecules provides new avenues to improve crop production in changing climatic conditions and the nutritional quality of foods. We present the rational combinations of small molecules with inhibitory and co-stimulatory effects and discuss future opportunities in this field.

Discovery of a Plant 14-3-3 Inhibitor Possessing Isoform Selectivity and In Planta Activity

Synthetic modulators of plant 14-3-3s are promising chemical tools both for understanding the 14-3-3-related signaling pathways and controlling plant physiology. Herein, we describe a novel small-molecule inhibitor for 14-3-3 proteins of Arabidopsis thaliana. The inhibitor was identified from unexpected products in a stock solution in dimethyl sulfoxide (DMSO) of an in-house chemical library. Mass spectroscopy, mutant-based analyses, fluorescence polarization assays, and thermal shift assays revealed that the inhibitor covalently binds to an allosteric site of 14-3-3 with isoform selectivity. Moreover, infiltration of the inhibitor to Arabidopsis leaves suppressed the stomatal aperture. The inhibitor should provide new insight into the design of potent and isoform-selective 14-3-3 modulators.

Small but powerful: RALF peptides in plant adaptive and developmental responses

Plants live in a highly dynamic environment and require to rapidly respond to a plethora of environmental stimuli, so that to maintain their optimal growth and development. A small plant peptide, rapid alkalization factor (RALF), can rapidly increase the pH value of the extracellular matrix in plant cells. RALFs always function with its corresponding receptors. Mechanistically, effective amount of RALF is induced and released at the critical period of plant growth and development or under different external environmental factors. Recent studies also highlighted the role of RALF peptides as important regulators in plant intercellular communications, as well as their operation in signal perception and as ligands for different receptor kinases on the surface of the plasma membrane, to integrate various environmental cues. In this context, understanding the fine-print of above processes may be essential to solve the problems of crop adaptation to various harsh environments under current climate trends scenarios, by genetic means. This paper summarizes the current knowledge about the structure and diversity of RALF peptides and their roles in plant development and response to stresses, highlighting unanswered questions and problems to be solved.