烟草NTHK1基因提高杨树根系的耐盐性

以受体杨树‘107号’和转入NTHK1（Nicotiana tabacum histidine kinase-1）基因的‘18-1’及‘18-4’的水培苗为材料,不同浓度的NaCl胁迫12d后,发现‘18-1’及‘18-4’的根长和根重显著大于‘107号’。以离体根段为材料,在400mmol·L-1NaCl溶液中胁迫60min后,‘107号’的K＋外渗量比‘18-1’和‘18-4’分别高49.34%和19.68%;在400mmol·L-1KCl或NaCl胁迫30min,‘107号’的电解质外渗率（REL）显著大于‘18-1’和‘18-4’;等渗的30%PEG对离体根段的REL影响很小。在400mmol·L-1NaCl溶液中添加200～400mmol·L-1的KNO3或KCl能显著增加离体根段的REL,并使不同基因型的REL差异更大。这表明,测定离体根段的K＋外渗量和REL可以快速鉴定不同基因型杨树的耐盐潜力。

NTHK1 of Tobacco Improves Salt Tolerance of Roots in Poplars

Effects of different concentrations of NaC1 on salt tolerance of roots in poplar ＇107＇ （Populus xeuramericana ＇Neva＇） and transgenic poplar ＇18-1＇ and ＇18-4＇ with NTHK1 （Nicotiana tabacurn histidine kinase-1） were investigated. The results showed that dry weight and length of roots in ＇18-1＇ and ＇18-4＇ were significantly higher than that of＇107＇. Under the stress of 400 mmol.L-1 NaCl for 60 min, the K＋ leakage amount of＇107＇ were 49.34% and 19.68% higher than those of＇l 8-1＇ and ＇18-4＇ respectively. And the relative electrolyte leakage （REL） of＇107＇ was also significantly higher than those of ＇18-1＇ and ＇18-4＇ after treatments of 400 mmol.L-1 KC1 or NaC1 for 30 min. But isotonic 30% PEG had little effect on the REL of root segment in vitro. The NaC1 solution added with 400 mmol.L-1KC1 or KNO3 significantly increased the REL of root segment in vitro, and made a greater difference between the different genotypes poplar. The results showed that the determination of K＋ leakage volume and REL of root segments in vitro could quickly identify potential salt tolerance of different genotypes of poplars.