Plant Omics Division, CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Council of Scientific & Industrial Research (CSIR), Bhavnagar, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
Physiol Plant. 2021 Dec;173(4):1448-1462. doi: 10.1111/ppl.13449. Epub 2021 Jun 7.
The plants endomembrane system of the cellular compartments with its complex membrane trafficking network facilitates transport of macromolecules. The endomembrane dynamics are essential for maintaining basic and specific cellular functions including adaptation to the extracellular environment. The plant vacuole serves as a reservoir for nutrients and toxic metabolites and performs detoxification processes to maintain cellular homeostasis. The overexpression of AlRab7, a vesicle trafficking gene from Aeluropus lagopoides, improved germination and growth and reduced ionic and oxidative stress in transgenics. Moreover, the root and shoot of transgenic tobacco showed differential accumulation of phytohormone ABA and IAA with different ionic stresses. The improved growth (root and shoot length) can be co-related with higher IAA accumulation with NaCl stress. The low Na /K ratio with different NaCl stress treatments indicates better ion homeostasis in transgenics. Furthermore, the increased stomatal density and higher number of open stomata on both leaf surfaces in transgenics during NaCl stress suggest better gaseous exchange/functioning of guard cells. The maintained or increased superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, and glutathione reductase antioxidative enzyme activities suggest that an extensive reactive oxygen species (ROS) scavenging system was triggered to detoxify cellular ROS, which remained at low levels in transgenics during the different stress treatments. Our results suggest that the AlRab7 transgenic tobacco ameliorates ionic stress by facilitating differential and selective ion transport at vacuolar membrane regulating hormone signaling, ROS homeostasis, stomatal development, and movement.
植物细胞区室的内膜系统及其复杂的膜运输网络促进了大分子的运输。内膜动力学对于维持基本和特定的细胞功能至关重要，包括适应细胞外环境。植物液泡作为营养物质和有毒代谢物的储存库，并进行解毒过程以维持细胞内稳态。从 Aeluropus lagopoides 中过度表达的囊泡运输基因 AlRab7，提高了转基因植物的萌发和生长，并降低了离子和氧化应激。此外，转基因烟草的根和茎表现出不同的植物激素 ABA 和 IAA 积累，与不同的离子胁迫有关。在 NaCl 胁迫下，生长（根和茎长）的提高可以与 IAA 积累的增加相关。不同 NaCl 胁迫处理的低 Na / K 比值表明转基因植物中更好的离子稳态。此外，在 NaCl 胁迫下，转基因植物的气孔密度增加，两面叶片的开放气孔数量增加，表明保卫细胞的气体交换/功能更好。维持或增加超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶、愈创木酚过氧化物酶和谷胱甘肽还原酶等抗氧化酶的活性表明，一种广泛的活性氧（ROS）清除系统被触发，以解毒细胞 ROS，在不同胁迫处理期间，ROS 在转基因植物中保持在低水平。我们的结果表明，AlRab7 转基因烟草通过在液泡膜上调节激素信号、ROS 稳态、气孔发育和运动来促进差异和选择性离子运输，从而减轻离子胁迫。
