Jiangsu Key Laboratory of Crop Genomics and Physiology, Jiangsu Key Laboratory of Crop Cultivation and Physiology, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou, China.
College of Horticulture and Landscape, Yangzhou University, Yangzhou, China.
Plant Cell Environ. 2024 Jan;47(1):38-48. doi: 10.1111/pce.14720. Epub 2023 Sep 13.
Hydrotropism is an important adaptation of plant roots to the uneven distribution of water, with current research mainly focused on Arabidopsis thaliana. To examine hydrotropism in tomato (Solanum lycopersicum) primary roots, we used RNA sequencing to determine gene expression of root tips (apical 5 mm) on dry and wet sides of hydrostimulated roots grown on agar plates. Hydrostimulation enhances cell division and expansion on the dry side compared with the wet side of the root tip. In hydrostimulated roots, the abscisic acid (ABA) biosynthesis gene ABA4 was induced more on the dry than the wet side of root tips. The ABA biosynthesis inhibitor Fluridone and the ABA-deficient mutant notabilis (not) significantly decreased hydrotropic curvature. Wild-type, but not the ABA biosynthesis mutant not, root tips showed asymmetric H efflux, with greater efflux on the dry than on the wet side of root tips. Thus, ABA mediates asymmetric H efflux, allowing the root to bend towards the wet side to take up more water.
向水性是植物根系适应水分不均匀分布的一种重要特性，目前的研究主要集中在拟南芥上。为了研究番茄（Solanum lycopersicum）主根的向水性，我们使用 RNA 测序来确定在琼脂平板上生长的受水力刺激的根的干燥侧和湿润侧的根尖（顶端 5mm）的基因表达。与根尖的湿润侧相比，水力刺激在干燥侧增强了细胞分裂和扩展。在受水力刺激的根中，与根尖的湿润侧相比，脱落酸（ABA）合成基因 ABA4 在干燥侧的诱导更多。ABA 合成抑制剂 Fluridone 和 ABA 缺陷突变体 notabilis (not) 显著降低了向水性曲率。野生型，但不是 ABA 合成突变体 not，根尖表现出不对称的 H 外排，与根尖的湿润侧相比，干燥侧的外排更大。因此，ABA 介导不对称的 H 外排，使根向湿润侧弯曲以吸收更多的水分。
