摘要
植物的耐盐能力与K^(+)的跨膜转运和体内的K^(+)稳态存在较为密切的关系。为探究植物的K^(+)吸收特性及其对盐分条件的响应,本研究以大麦耐盐品种‘苏农6472’(SN)和盐敏感品种‘Gairdner’(GD)为试验材料,采用Michaelis-Menten模型和一般线性模型相结合的方法,比较了NaCl对两个大麦品种的K^(+)吸收动力学特征和四乙基铵(TEA)非敏感性K^(+)吸收的影响。试验结果表明:大麦K^(+)吸收动力学曲线符合v=Vmax×S/(S+Km)+kS模型,50 mmol/L NaCl降低了Vmax值和k值,提高了Km值,且SN比GD具有更高的Vmax、Km和k值;随NaCl水平的提高,大麦的K^(+)总吸收速率和TEA非敏感性K^(+)吸收速率都呈先增后降的趋势,但TEA非敏感途径对K^(+)吸收的贡献率随Na Cl水平的提高呈下降趋势;在100 mmol/L NaCl条件下,SN的TEA非敏感途径贡献率仍保持在较高水平(51.3%),而GD仅16.7%;外源添加Ca^(2+)促进了SN的TEA非敏感性K^(+)吸收,但对GD并不总表现出促进作用;外源脯氨酸(Pro)和赖氨酸(Lys)促进了两个大麦品种的TEA非敏感性K^(+)吸收,而缬氨酸(Val)的影响因Na Cl水平和大麦品种而异;环腺苷酸(cAMP)增加了SN的TEA非敏感性K^(+)吸收,但对GD仅在低NaCl条件下有促进作用。
Potassium transport across plasma membrane and potassium homeostasis in cells have close relation to the salt tolerance of plants.In order to explore crop's potassium uptake characteristics and their responses to NaCl in environment,two barley varieties,'Sunong6472'(SN,salt-tolerant)and'Gairdner'(GD,salt-sensitive)were used as experimental materials.With the combine of Michaelis-Menten model and general linear mode,the effects of NaCl on the kinetic characteristics of K^(+)uptake and TEA(tetraethylammonium)-insensitive K^(+)uptake were compared between two barley varieties.The experimental results indicated that the kinetic curve of K^(+)uptake in barley conformed to the model v=V_(max)×S/(S+K_(m))+kS.50 mmol/L NaCl increased K_(m) and decreased V_(max) and k,and SN had higher V_(max),K_(m) and k than GD.With the increase of NaCl levels,both total potassium uptake rate and its tetraethylammonium(TEA)insensitive part were stimulated at first and then in hibited,and the contribution of TEA-insensitive pathway decreased.Under 100 mmol/L NaCl stress,SN still remained a high contribution rate(51.3%),while it was only 16.7%in GD.Addition of Ca^(2+)significantly promoted TEA-insensitive K^(+)uptake of SN,but it did not always exhibit a promotive effect on GD.Exogenous proline and lysine also increased TEA-insensitive K^(+)uptake,whereas the effects of valine changed with both NaCl levels and barley varieties.cAMP also increased TEA-insensitive K^(+)uptake of SN,while increased that of GD only at low NaCl level.
作者
汪晓丽
陈天鹏
王小兵
陈博文
王莎
Wang Xiaoli;Chen Tianpeng;Wang Xiaobing;Chen Bowen;Wang Sha(College of Environmental Science and Engineering,Yangzhou University,Yangzhou,225127)
出处
《分子植物育种》
北大核心
2025年第8期2675-2682,共8页
Molecular Plant Breeding
基金
江苏省农业科技自主创新资金项目[CX(20)3082]
土壤与农业可持续发展国家重点实验室开放项目(Y2016-0017)共同资助。
关键词
钾吸收
氯化钠
四乙基铵
大麦
Potassium uptake
Sodium chloride
Tetraethylammonium
Barley
