摘要
以耐盐小麦品种‘德抗961’和盐敏感小麦品种‘鲁麦15’为材料,研究小麦根Na+、K+吸收特性及其与耐盐性关系。结果表明,2个小麦品种根K+吸收动力学曲线均符合Michaelis-Menten方程,即V=Vmax×[S]/([S]+Km)+k×[S]。低浓度(低于25mmol·L-1)NaCl处理对根高亲和K+吸收系统转运K+具有促进作用,对耐盐品种‘德抗961’的促进作用更大。小麦根高亲和K+吸收系统是通过K+/H+同向转运,而不是K+/Na+同向转运。NaCl处理对根低亲和K+吸收系统有抑制作用,对盐敏感品种‘鲁麦15’的抑制作用更大。NaCl处理导致2个小麦品种根和叶片中的K+含量显著下降,Na+含量显著升高,但‘德抗961’根和叶片中的K+含量均显著高于‘鲁麦15’,‘德抗961’根中Na+含量显著高于‘鲁麦15’,而其叶片中Na+含量显著低于‘鲁麦15’,从而保证NaCl胁迫下其叶片较高的K+/Na+比。非选择性阳离子通道是小麦根Na+吸收的主要途径,K+通道是Na+吸收的一条重要途径。这些结果表明小麦部分通过调节根系K+吸收系统而维持叶片较高的K+/Na+比,从而提高其耐盐性。
Salt-tolerant wheat cultivar ＇DK961＇ investigate the characteristics of Na＋ and K＋ uptake and salt-sensitive wheat cultivar ＇LM15＇ were used to and correlation with salt tolerance. Results showed that K＋ uptake kinetics of roots was fitted to the Michaelis-Menten equation, namely V=Vmax ×[S]/（[S]＋Km）＋kx[S], for both cultivars. Low concentration NaCl （〈25 mmol.L-1） treatment significantly enhanced high-affinity K＋ uptake system, and the effects on ＇DK961＇ was stronger than that on ＇LM15＇. High-affinity K＋ uptake of wheat roots possibly is driven by K＋/H＋ symporter instead of K＋/Na＋ symporter. NaCl treatment inhibited low-affinity K＋ uptake system, and the effects on ＇LM15＇ was stronger than that on ＇DK961＇. The K＋ content in roots and leaves significantly decreased in response to NaCl stress, while the Na＋ content significantly increased under NaCl stress. Under NaCI stress, K＋ content in roots and leaves of ＇DK961＇ was significantly higher than that of ＇LM 15＇, and the Na＋ content of roots in ＇DK961＇ was significantly higher than that in ＇LM 15＇. However, leaf Na＋ content of ＇DK961＇ was significantly lower than that of ＇LM15＇ under NaCl stress. Therefore, K＋/Na＋ ratio in leaves of ＇DK961＇ was higher than that in ＇LM15＇ in response to NaCl stress. NSCCs （non-selective cation channels） are the main pathways for Na＋ uptake, and K＋ channels mediate Na＋ uptake. These results suggested that wheat enhanced salt tolerance partly via regulating root K＋ uptake system contributed to high K＋/Na＋ ratio of leaves.
出处
《植物生理学报》
CAS
CSCD
北大核心
2013年第1期34-40,共7页
Plant Physiology Journal
基金
国家自然科学基金(30270793)
国家支撑计划项目(2009BADA7B05)
