Yuan Ting-Ting, Xu Heng-Hao, Zhang Kun-Xiao, Guo Ting-Ting, Lu Ying-Tang
State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
Plant Cell Environ. 2014 Jun;37(6):1338-50. doi: 10.1111/pce.12233. Epub 2013 Dec 10.
Glucose functions as a hormone-like signalling molecule that modulates plant growth and development in Arabidopsis thaliana. However, the role of glucose in root elongation remains elusive. Our study demonstrates that high concentrations of glucose reduce the size of the root meristem zone by repressing PIN1 accumulation and thereby reducing auxin levels. In addition, we verified the involvement of ABA INSENSITIVE 5 (ABI5) in this process by showing that abi5-1 is less sensitive to glucose than the wild type, whereas glucose induces ABI5 expression and the inducible overexpression of ABI5 reduces the size of the root meristem zone. Furthermore, the inducible overexpression of ABI5 in PIN1::PIN1-GFP plants reduces the level of PIN1-GFP, but glucose reduces the level of PIN1-GFP to a lesser extent in abi5-1 PIN1::PIN1-GFP plants than in the PIN1::PIN1-GFP control, suggesting that ABI5 is involved in glucose-regulated PIN1 accumulation. Taken together, our data suggest that ABI5 functions in the glucose-mediated inhibition of the root meristem zone by repressing PIN1 accumulation, thus leading to reduced auxin levels in roots.
葡萄糖作为一种类似激素的信号分子，调节拟南芥的植物生长和发育。然而，葡萄糖在根伸长中的作用仍不清楚。我们的研究表明，高浓度的葡萄糖通过抑制PIN1积累从而降低生长素水平，减小根分生组织区的大小。此外，我们通过证明abi5-1对葡萄糖的敏感性低于野生型，证实了ABA不敏感5（ABI5）参与了这一过程，而葡萄糖诱导ABI5表达，且ABI5的诱导过表达减小了根分生组织区的大小。此外，在PIN1::PIN1-GFP植物中ABI5的诱导过表达降低了PIN1-GFP的水平，但与PIN1::PIN1-GFP对照相比，葡萄糖在abi5-1 PIN1::PIN1-GFP植物中降低PIN1-GFP水平的程度较小，这表明ABI5参与了葡萄糖调节的PIN1积累。综上所述，我们的数据表明，ABI5通过抑制PIN1积累在葡萄糖介导的根分生组织区抑制中发挥作用，从而导致根中生长素水平降低。
