烟草NTHK1基因提高杨树根系的耐盐性

NTHK1 of Tobacco Improves Salt Tolerance of Roots in Poplars

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。

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.