Coordination of vacuolar proton-pumps during cold acclimation

植物种类的地理分布以及作物的生长和产量受到其耐低温性的限制。来自温带地区的植物在暴露于低但不冻结的温度下增加其抗冻能力，这一过程被称为冷驯化，而对冷敏感的植物却没有这样做。对低温敏感的植物来说，细胞膜损伤是造成冻害的主要原因，而液泡H+- atp酶（v - atp酶）失活导致细胞质酸化已被报道为冷暴露后的主要事件之一。我们已经证明，拟南芥的冷驯化涉及到v - atp酶活性的增加，这需要第二种酶的存在和活性，即液泡H+-PPase （V-PPase）。我们现在建议确定两个质子泵在冷驯化过程中相互作用的分子机制，以及它们通过s -酰化进行可逆修饰的功能。此外，我们将通过遗传编码传感器（pH值和ATP/ADP比率）以及代谢组学和脂质组学方法，对液泡H+泵在冷驯化过程中的作用进行全面分析。基于这些预期的见解，将开发出提高作物耐寒性的新策略。

The geographical distribution of plant species as well as the growth and yield of crop plants are limited by their tolerance to low temperatures. Whereas plants from temperate regions increase their freezing tolerance during exposure to low but non-freezing temperatures in a process termed cold acclimation, chilling-sensitive plants fail to do so. Damage to cellular membranes is the major cause of freezing injury in chilling-sensitive plants and inactivation of the vacuolar H+-ATPase (V-ATPase) leading to cytosolic acidification has been reported to be one of the primary events after cold exposure. We have shown that cold acclimation in Arabidopsis involves an increase in V-ATPase activity that requires the presence and activity of a second enzyme, the vacuolar H+-PPase (V-PPase).We now propose to determine the molecular mechanism underlying the interplay of the two proton-pumps during cold acclimation as well as the function of their reversible modification via S-acylation. Moreover, we will perform a comprehensive analysis of the role of vacuolar H+-pumps during cold acclimation via genetically encoded sensors (pH and ATP/ADP ratio) as well as by metabolomics and lipidomics approaches. Based on the expected insights novel strategies for improved cold tolerance of crop plants will be developed.