磷饥饿对番茄幼苗H+分泌及Pi吸收的影响

磷饥饿条件下番茄幼苗的H⁺分泌速率明显提高。质膜质子泵专一性抑制剂钒酸盐能显著抑制番茄幼苗的H⁺分泌,也能显著抑制其Pi吸收。此结果表明,磷饥饿时番茄幼苗Pi吸收速率的变化与H⁺分泌速率的变化之间可能具有一定的相关性,并进一步暗示质膜H⁺-ATPase可能参与其中。本文结果还表明,Pi/H⁺的准量关系约为1:1。

Effects of phosphate starvation on H+ extrusion and Pi uptake of tomato seedlings

Changes of H⁺ extrusion rates and the relationship between H⁺ extrusion and Pi uptake of tomato seedlings during phosphate starvation were studied. The results revealed that phosphate starvation increased the H⁺ extrusion rates of tomato seedlings and it also indicated that vanadate, a specific inhibitor of PM H⁺-ATPase, strongly inhibited not only Pi uptake but also H⁺ extrusion of tomato seedlings, which were exhibited more strongly in Pi starved conditions than in the control. These results indicated that the changes of Pi uptake rates and H⁺ extrusion rates may be related, and furthermore, the PM H⁺-ATPase may be involved in these changes during phosphate starvation. The results also revealed that the quasi-ratio of Pi/H⁺ was about 1:1.