两种植物在不同生长期控制Na^+流入的差异

Influence of Growth Stage on Na^+ Influx in Two Plant Species

控制Na^+进出植物根系的能力是研究植物耐盐机制的关键,但由于测量技术和条件的限制,目前关于植物根系Na^+内流速率受生长阶段的影响还无相关研究。该研究采用非损伤微测技术,选取小麦与野大麦为代表材料,研究了单子叶甜土植物与单子叶盐生植物在不同生长阶段下的根系Na+内流速率差异。结果表明:2个盐浓度处理下野大麦和小麦根系的Na^+内流速率都随生长而逐渐增大:2~3叶期,2个材料之间Na^+内流速率差异不显著(P>0.05);4叶期时,浓度为25 mmol/L NaCl处理下野大麦比小麦低10%,但差异也不显著(P>0.05);浓度为100 mmol/L NaCl时野大麦比小麦高19%,差异显著(P<0.05)。可见,生长阶段能显著影响植物控制Na^+流入的能力,4叶期以后的野大麦比小麦吸收更多的Na^+。因此,在比较植物耐盐能力以及相关研究时应考虑生长阶段的影响。

The ability of controlling Na＋ influx and efflux of plant roots is the key to study the mechanism of salt tolerance in plants.However,due to the limitation of measurement techniques and conditions,the influence of growth stage on the ability of Na＋ influx in plants remains elusive. Gramineous halophyte wild barley and glycophyte wheat were chosen there,for testing the unidirectional Na＋ influxes of monocotyledonous at 2 leaves,3 leaves and 4 leaves stages,respectively. The micro-electrode ion flux estimation technique experiments showed that Na＋ influx increased obviously with the plant growth stage in both species.There was no significant difference between wild barley and wheat under 2-3 leave stage（P〉0.05）. At 4 leaves stage,wild barley was lower by 10% than that of wheat under 25 mmol/L NaCl（P〉0.05）,but under 100 mmol/L NaCl,Na＋ influx of wild barley was significantly higher by 19% than that of wheat（P〈0.05）. These indicated that growth stage had obvious influence on the Na＋ fluxes in both species;and wild barley had stronger ability of Na＋ influx than wheat under 4 leaves stage. Therefore,plant growth stage should be considered in salt tolerance and relative researches.