外源亚精胺对盐胁迫下水稻根系活力及叶片光合色素含量的影响

Effect of Exogenous Spermidine on the Root Vigor and the Content of Photosynthetic Pigment in the Leaf of Rice Cultivar under Salt Stress

[目的]研究外源亚精胺(Spd)对盐胁迫下抗盐能力不同的2个水稻品种的根系活力及叶片光合色素含量的影响。[方法]选用由国际水稻研究所(IRRI)提供的已确定具植株耐盐性差异的一组籼稻品种——Pokkali(耐盐)和Peta(盐敏感)为材料,研究外源Spd对盐胁迫下2个品种根系活力及叶片光合色素含量的影响。[结果]200 mmol/L NaCl处理下,随着盐胁迫处理时间的延长,水稻根系活力呈现先升高后降低的变化趋势,盐敏感品种Peta根系活力的下降幅度大于耐盐品种Pokkali;而外源Spd处理下Pokkali根系活力比Peta占优势;耐盐品种Pokkali的叶绿素(Chl)和类胡萝卜素(Car)含量较对照均有所升高,且Chl的升高幅度明显大于Car,使Car/Chl比对照有显著下降,而Peta仅Car升高,Chl较对照则有所下降;外源Spd处理提高了盐处理下2个品种Chl和Car含量以及Chla/Chlb,且Pokkali的Chl含量升幅较大。[结论]Spd对水稻根系盐胁迫具有缓解作用,降低根系的伤害程度;能提高水稻光合色素含量,缓解盐胁迫对水稻叶绿体精细结构的破坏,降低盐胁迫对光合色素蛋白复合体的伤害,从而提高水稻光合能力。

[Objective]The research on the effect of exogenous spermidine（Spd） on the root vigor and the content of photosynthetic pigment in the leaf of two rice cultivars（Pokkali with salt-tolerant and Peta with salt-sensitive） were studied.[Method] Two rice varieties-Pokkali with the resistance to salt and Peta with the sensitivity to salt were introduced from IRRI and the effect of exogenous Spd on the root vigor and the content of photosynthetic pigment in the leaf of them was analyzed.[Results] The results showed that the root vigor of rice seedlings under salt stress of 200 mmol/L NaCl was increased at first and then decreased with the treatment time-lasting,which descending range of Peta was greater than that of Pokkali;and under the treatment of exogenous Spd,the resistance of Pokkali to salt stress was obviously stronger than that of Peta,which advantage was significant.The content of both Chl and Car in the Pokkali was more than those of CK and the increment range of Chl was larger than that of Car so that the ratio of Car/Chl was significantly decreased.In the variety-Peta,the content of Car was raised and the content of Chl was decreased compared with CK.The treatment of exogenous Spd could improve the content of Chl and Car,the ratio of Chla/Ch1b of two varieties,which were under salt stress,and there was larger increment in the content of Chl in Pokkali compared with Peta.[Conclusion] The treatment of exogenous Spd had the remission effect on the salt stress to root for less damage of salt to root,to the destroy of chloroplast structure for higher content of photosynthetic pigment and reduced the damage of salt stress to the compound of photosynthetic pigment peotien for higher photosynthetic capacity.