Ayyoub Anam, Yu Xiuyuan, Zhang Xingjian, Gao Chen, Li Jiazhou, Yin Shijiao, Chen Shaolin, Liesche Johannes
College of Life Sciences, Northwest A&F University, 712100 Yangling, China.
Biomass Energy Center for Arid and Semiarid Lands, Northwest A&F University, 712100 Yangling, China.
J Exp Bot. 2024 Dec 4;75(22):7019-7030. doi: 10.1093/jxb/erae370.
The cytoplasm of most plant cells is connected by membrane-lined cell wall channels, the plasmodesmata (PD). Dynamic regulation of sugar, hormone, and protein diffusion through PD is essential for plant development and stress responses. Understanding this regulation requires knowledge of factors and mechanisms that control PD permeability through the modulation of callose levels in the cell wall around PD openings. We investigated PD regulation in leaf epidermal cells in relation to drought stress in Arabidopsis. PD-mediated cell wall permeability was decreased by drought stress and the hormone abscisic acid (ABA), and we tested how this related to several PD-associated genes with drought-responsive expression. Mutants of NON-RACE SPECIFIC DISEASE RESISTANCE/HIN1 HAIRPIN-INDUCED-LIKE 12 (NHL12) showed relatively low PD permeability that was unaffected by drought or ABA treatment. Overexpression of NHL12 in Nicotiana benthamiana epidermal cells increased PD permeability. Moreover, we showed that NHL12 can potentially interact with the callose synthase regulator NHL3 and we explored the effect of NHL12 abundance and/or lower interface permeability on ABA signaling genes. Our results indicate that NHL12 is a drought-responsive negative regulator of PD callose levels and, thereby, interface permeability. Results are discussed in relation to PD function during drought stress and the regulation of intercellular transport.
大多数植物细胞的细胞质通过有膜衬里的细胞壁通道——胞间连丝（PD）相连。糖、激素和蛋白质通过胞间连丝的动态调节对植物发育和应激反应至关重要。要了解这种调节，需要知道通过调节胞间连丝开口周围细胞壁中胼胝质水平来控制胞间连丝通透性的因素和机制。我们研究了拟南芥叶片表皮细胞中与干旱胁迫相关的胞间连丝调节。干旱胁迫和激素脱落酸（ABA）会降低胞间连丝介导的细胞壁通透性，我们测试了这与几个具有干旱响应表达的胞间连丝相关基因之间的关系。非种族特异性抗病性/HIN1发夹诱导样12（NHL12）突变体显示出相对较低的胞间连丝通透性，且不受干旱或ABA处理的影响。在本氏烟草表皮细胞中过表达NHL12会增加胞间连丝通透性。此外，我们表明NHL12可能与胼胝质合酶调节因子NHL3相互作用，并且我们探究了NHL12丰度和/或较低的界面通透性对ABA信号基因的影响。我们的结果表明，NHL12是干旱响应的胞间连丝胼胝质水平的负调节因子，从而也是界面通透性的负调节因子。本文结合干旱胁迫期间胞间连丝的功能以及细胞间运输的调节对结果进行了讨论。
