外源NO对NaCl胁迫下番茄幼苗离子吸收及分布的影响

Effects of Exogenous Nitric Oxide on Ion Absorption and Distribution of Tomato Seedlings under NaCl Stress

在100mmolL-1NaCl胁迫下,研究了外源NO供体硝普钠(SNP)处理对2个耐盐性不同的番茄(Lycopersicon esculentum Mill.)基因型幼苗根、茎和叶离子吸收和分布的影响。结果表明,外源NO显著降低盐胁迫下番茄幼苗根、茎和叶中Na+、Cl-含量,促进K+、Ca2+和Mg2+含量并提高K+/Na+、Ca2+/Na+和Mg2+/Na+值,促进根对K+、Ca2+的选择性吸收(SK/Na、SCa/Na)和K+、Ca2+向地上部的选择性运输(SK/Na、SCa/N)a。SNP单独处理时对以上各指标没有显著影响。在相同的处理条件下,盐敏感品种的Na+、Cl-在根、茎和叶中累计量均低于耐盐品种,而K+、Ca2+和Mg2+的累计相反;根向介质吸收SK/Na、SCa/Na,向茎、叶运输的SK/Na、SCa/Na值均较低。以上结果表明,外源NO能通过降低离子毒害,改善植株体内的养分平衡,缓解NaCl胁迫对番茄幼苗造成的伤害,增强番茄幼苗的耐盐能力。

The effects of sodium nitropprusside （SNP, an exogenous nitric oxide donor） on ion absorption and distribution of roots, stems and leaves of two tomato （Lycopersicon esculentum Mill.） seedlings （salt-tolerant and salt-sensitive genotype ） were investigated under 100 mmol L-1 NaCl stress condition. The results showed that under NaCl stress, contents of Na＋ and Cl- were significantly decreased, contents of K＋, Ca2＋ and Mg2＋, K＋/Na＋, Ca^2＋/Na＋ and Mg^2＋/Na＋ values, SK/Na （absorption） value and SCa/Na （absorption） value, SKNa （transportation） value and SCa/Na （transportation） value were obviously increased in the roots, stems and leaves of tomato seedlings by exogenous nitric oxide. SNP treatment alone had no significant effects on above parameters. At the same treatments, the aceumlation of Na＋ and Cl- in the roots, stems and leaves was higher in salt-sensitive cuhivar than in salt-tolerant one, but the reverse was found for K＋, Ca2＋ and Mg2＋. SKNa （absorption） value and SCa/Na （absorption） value, SKNa （transportation） value and SCa/Na （transportation） value in salt-sensitive cuhivar were lower than in salt-tolerant one. The results showed that NO could decrease Na＋ and Cl- toxicity, improve the nutrient balance, alleviate the damage of NaCl stress on tomato and elevate the salt tolerance of plants. seedlings