生长素调控极性运输载体PIN2质膜丰度与降解

摘要

The effects of long-term (8 h) treatments with exogenous auxins on auxin efflux transporter PIN2-GFP plasma membrane (PM) abundance,and low temperature,KCN and auxin receptors TIR1/AFBs mutation on auxin regulation of PIN2-GFP PM abundance,and ConA,a vacuolar H +-ATPase inhibitor,on vacuolar accumulation of PIN2-GFP in wild-type and auxin receptor quadruple mutants tir1afb1,2,3 cells in Arabidopsis were systematically studied.The results revealed that exogenous auxins down-regulated PIN2-GFP PM abundance through TIR1/AFB-mediated signaling and promoted PIN2-GFP internalization,intracellular membrane trafficking,and vacuolar degradation,indicating that auxin feedback regulates PIN2-GFP PM levels through TIR1/AFB-mediated signaling and inhibits excessive transport of intracellular auxin out of the cell.%主要观察了外源生长素长时间(8 h)处理对拟南芥生长素极性输出载体PIN2-GFP质膜丰度的影响,低温、KCN处理和生长素受体突变对生长素调控质膜PIN2-GFP丰度的影响,以及液泡H+-ATPase抑制剂ConA对野生型和生长素受体四突变体tir1aafb1,2,3液泡中PIN2-GFP积累的影响.结果表明:外源生长素通过其受体TIR1/AFB介导的信号途径下调质膜PIN2-GFP的丰度,促进PIN2-GFP的内吞、胞内运输和液泡降解.暗示生长素通过TIR1/AFB介导的信号途径反馈调控质膜PIN2-GFP的水平,从而阻止了胞内生长素的过多输出.