N-glycosylation is involved in stomatal development by modulating the release of active abscisic acid and auxin in Arabidopsis

作者：Qingsong Jiao, Tianshu Chen, Guanting Niu, Huchen Zhang, Changfang Zhou, Zhi Hong · 发表于：Journal of Experimental Botany · 年份：2020 · DOI：10.1093/jxb/eraa321 · 被引用次数：31 · 研究领域：Plant Molecular Biology Research、Polysaccharides and Plant Cell Walls、Plant Stress Responses and Tolerance

Asparagine-linked glycosylation (N-glycosylation) is one of the most important protein modifications in eukaryotes, affecting the folding, transport, and function of a wide range of proteins. However, little is known about the roles of N-glycosylation in the development of stomata in plants. In the present study, we provide evidence that the Arabidopsis stt3a-2 mutant, defective in oligosaccharyltransferase catalytic subunit STT3, has a greater transpirational water loss and weaker drought avoidance, accompanied by aberrant stomatal distribution. Through physiological, biochemical, and genetic analyses, we found that the abnormal stomatal density of stt3a-2 was partially attributed to low endogenous abscisic acid (ABA) and auxin (IAA) content. Exogenous application of ABA or IAA could partially rescue the mutant's salt-sensitive and abnormal stomatal phenotype. Further analyses revealed that the decrease of IAA or ABA in stt3a-2 seedlings was associated with the underglycosylation of β-glucosidase (AtBG1), catalysing the conversion of conjugated ABA/IAA to active hormone. Our results provide strong evidence that N-glycosylation is involved in stomatal development and participates in abiotic stress tolerance by modulating the release of active plant hormones.