Ameliorative effects of potassium on drought-induced decreases in fiber length of cotton(Gossypium hirsutum L.) are associated with osmolyte dynamics during fiber development  

作　　者：Wenqing Zhao Haoran Dong Rizwan Zahoor Zhiguo Zhou John L.Snider Yinglong Chen Kadambot H.M.Siddique Youhua Wang 

机构地区：[1]Key Laboratory of Crop Ecophysiology and Management of Ministry of Agriculture,Nanjing Agricultural University,Nanjing 210095,Jiangsu,China [2]Jiangsu Collaborative Innovation Center for Modern Crop Production(JCIC-MCP),Nanjing Agricultural University,Nanjing 210095,Jiangsu,China [3]The UWA Institute of Agriculture,The University of Western Australia,Perth,WA 6001,Australia [4]The Department of Crop and Soil Sciences,University of Georgia,Tifton,GA 31794,USA [5]State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling 712100,Shannxi,China [6]University of the Agriculture,Faisalabad Sub-campus Depalpur,Okara,Pakistan

出　　处：《The Crop Journal》2019年第5期619-634,共16页作物学报（英文版）

基　　金：financial support from the National Key Research and Development Program of China (2018YFD1000900);Jiangsu Collaborative Innovation Center for Modern Crop Production (JCIC-MCP);Jiangsu Overseas Research and Training Program for University Prominent Young and Middle-aged Teachers and President (2016), China

摘　　要：Fiber length of cotton(Gossypium hirsutum L.)decreases under drought stress,potassium(K)could diminish the decreased caused by drought,but the mechanism associated with this alleviation effect is not clear.We evaluated the effect of K on fiber elongation using two cotton cultivars,Simian 3 and Siza 3,grown in well-watered and drought-stressed conditions.Potassium fertilizer(K2O)was applied 0,150,or 300 kg ha?1 in each growing condition.Drought stress reduced the final fiber length due to a decline in the maximum rate of rapid elongation(Vmax,mmday?1).The application of K alleviated the droughtinduced fiber length reduction by increasing Vmax.At 10 and 15 days post-anthesis(DPA),drought significantly reduced osmotic potential(OP)and increased K+and malate contents at all K rates,relative to well-watered conditions,which was associated with increased activities of phosphoenolpyruvate carboxylase(PEPC),V-ATPase,PPase,and PM H+-ATPase in cotton fiber.However,the relative contribution of K+and malate to OP declined under drought in comparison with well-watered condition.Compared with control without K,K application decreased OP and increased the accumulation of osmolytes(K+,malate and soluble sugar)as well as the activities of related enzymes in fiber irrespective of water treatments.Moreover,K application increased osmotic adjustment during drought,and improved the contribution of K+and malate to OP,especially under drought stress.This study showed that drought decreased fiber length by reducing Vmax,and K application ameliorates the decline in fiber elongation due to drought by enhancing osmolytes accumulation and their contribution to OP in fiber cells.Fiber length of cotton(Gossypium hirsutum L.) decreases under drought stress, potassium(K)could diminish the decreased caused by drought, but the mechanism associated with this alleviation effect is not clear. We evaluated the effect of K on fiber elongation using two cotton cultivars, Simian 3 and Siza 3, grown in well-watered and drought-stressed conditions. Potassium fertilizer(K2 O) was applied 0, 150, or 300 kg ha-1 in each growing condition. Drought stress reduced the final fiber length due to a decline in the maximum rate of rapid elongation(Vmax, mm day-1). The application of K alleviated the droughtinduced fiber length reduction by increasing Vmax. At 10 and 15 days post-anthesis(DPA),drought significantly reduced osmotic potential(OP) and increased K+and malate contents at all K rates, relative to well-watered conditions, which was associated with increased activities of phosphoenolpyruvate carboxylase(PEPC), V-ATPase, PPase, and PM H+-ATPase in cotton fiber. However, the relative contribution of K+and malate to OP declined under drought in comparison with well-watered condition. Compared with control without K, K application decreased OP and increased the accumulation of osmolytes(K+, malate and soluble sugar) as well as the activities of related enzymes in fiber irrespective of water treatments. Moreover, K application increased osmotic adjustment during drought, and improved the contribution of K+and malate to OP, especially under drought stress. This study showed that drought decreased fiber length by reducing Vmax, and K applicationameliorates the decline in fiber elongation due to drought by enhancing osmolytes accumulation and their contribution to OP in fiber cells.

关 键 词：Cotton(Gossypium hirsutum) Fiber length DROUGHT stress POTASSIUM application OSMOLYTE 

分 类 号：TN2[电子电信—物理电子学]