棉花不同根冠互作类型钾吸收的长距离信号调控机制

Potassium (K+) is a major plant nutrient with many biochemical and physiological functions. Cotton has a high demand for potassium. However, wide-spread of K deficiency in cotton has occurred in many countries. Our previous field experiment determined the two types of root-shoot interactions of potassium uptake. In this project, we will select cotton cv. CCRI41, SCRS22 and CCRI49, the cultivars differ in their potassium uptaking efficiency from the perspective of long-distance signal regulation. Perform grafting experiment, analysis the response of root and shoot induced by potassium deficiency, the function of root-to-shoot signal regulation of potassium uptake, and mechanism of shoot-to-root feedback signal regulation of potassium uptake in cotton, to reveal the cotton root-shoot interactions of physiological mechanism of potassium nutrition efficiency. The disclosure of mechanism of root-shoot interaction of potassium uptake will lead better to understand the complexity of the potassium nutrition regulation, as to provide the basis for cotton nutrition physiology potassium, in order to provide guidance for cotton potassium efficient breeding and cultivation.

棉花是喜钾作物，目前生产上因缺钾而导致的棉花早衰问题日趋严峻。研究发现棉花钾吸收存在不同的根冠互作类型，一种是根系起主要调节作用，另一种是地上部反馈调节起主要调节作用，但其生理机制尚不清楚。本研究以钾低效棉花品种中棉所41、钾高效品种鲁棉研22和中棉所49为材料，通过两种嫁接方式从长距离信号调控角度分析不同根冠互作类型的两组材料根系对钾胁迫的响应差异、根-冠信号对钾吸收的调控作用、地上部对钾胁迫的反应、冠-根信号反馈调节植株吸钾能力等方面，探讨棉花不同根-冠互作类型钾吸收的长距离信号调控机制。阐明棉花钾吸收的根-冠互作机制，为棉花钾营养生理、棉花钾高效育种和栽培提供理论依据和技术支撑。

棉花是喜钾作物，目前生产上因缺钾而导致的棉花早衰问题日趋严峻。研究发现棉花钾吸收存在不同的根冠互作类型，一种是根系起主要调节作用，另一种是地上部反馈调节起主要调节作用，但其生理机制尚不清楚。本研究以钾低效棉花品种中棉所41、钾高效品种鲁棉研22和中棉所49为材料，研究发现在低钾条件下，中41-鲁22嫁接组合中，以鲁22为接穗的处理缺钾症状得到缓解，干物质积累、光合参数、钾含量、叶片激素含量和根系形态等生理表型参数均显著高于以中41为地上部的嫁接处理。中41-中49嫁接组合中，以中49为砧木的处理显著的缓解植株缺钾症状，上述生理表型参数均显著高于以中41为砧木的嫁接处理。说明嫁接组合中41-鲁22中接穗对钾吸收影响较大，而中41-中49嫁接组合砧木对钾吸收影响显著。地上部主导型中41-鲁22嫁接组合与根系主导型加中41-中49的嫁接组合相比，木质部汁液中ABA和ZR+Z水平与钾吸收动力学参数相关性更大，说明ABA和ZR+Z调控地上部主导型嫁接植株对钾吸收影响大于根系主导型降低。中41-鲁22与中41-中49的嫁接组合相比，韧皮部汁液中ABA和ZR+Z水平与钾吸收动力学参数相关性更大，说明在地上部主导型的嫁接植株中，冠-根信号ABA和ZR+Z对钾吸收调控强度大于根系主导型的嫁接植株。