一种钙调素结合蛋白对小麦质膜H~ -ATP酶活性的调节

植物生长素参与植物生长和发育诸多方面的调节。研究表明，生长素的调节机制与Caz”的存在紧密相关。Caz”在植物激素的信号传导中起着信使作用（Hepler和Randy1985），它与钙调素（Ca．－－－urr－ulin，CaM）结合参与了各种类型植物激素应答反应的调节。现已查明，CaM的诸多功能常受其内源性结合蛋白的调控。本研究组曾分离得到一种新的植物CaM结合蛋白——CaMBP－10o实验证明，CaMBP－10通过与CaM的特异性结合显著抑制了CaM对其靶酶的激活（尚克进等1991）。前期工作还发现CaMBP－10对生长素诱导的小麦芽鞘伸长和质子外排均有…

Regulatory Action of a Calmodulin Bindsng Protein on Activi-ty of the Plasma Membrane H~ -ATPase in Wheat

CaM BP-10 (BP-10) is anovel endogenous calmodalin (CaM )-binding Protein tha was observed in andisolated from Plant. In our prelidrimpstudies it has been shown tha BP-10specifically inhibits adrin (IAA)-in-duced coleoptile elongallon and pbonsecrehon. In oIder to inveshgatewhether BP10 inhibitS Picton secrehonand cell elongaion thidgh inhibitingthc achvity of Plasrna mernbare (PM)H -ATPase, the effect of BP-10 on theachvity of wheat coleoptile PM H -AT-Pase has been studied. It was observedtha neither IAA nor BP-10 had any effect on the achvity of PM H -ATPaSein vitro. In vho, however, the activity0f Al-treated PM H -ATPaSe washigher than tha of the control, and BP-10 peilicanx iwhbital atinduedachvity by 87- 8% (rig. 1) - In addi-hon, the inhibitory effect cotild be re-versed by IAA after BPIO was removedfrom the mediurn, and it could also beovercome bV the addihon of CaM.Therefore, it appears that BP-10 in-hibits cell responses to andn by affect-ing the achvity of PM H -ATPase andthereby inhibiting Proton secrehon. As aresult, cell elongaon is inhibited. AndCaM is also involved in this pmeess-