摘要：
To explore the response mechanism and effect of salt stress on sucrose accumulation and activities of su-crose synthase (SS), sucrose phosphate synthase(SPS), three germplasms were cultured by barrel plant and soil culture until booting stage under six concentration grades of NaCl solution. The effect of salt stress on the appearance, sucrose con-tent, soluble sugar content, SS activity and SPS activity of rice plants were studied. The results showed that salt stress de-creased rice height, tiller number, total leaf area and made leaves to wither, and the inhibitory rate increased with the in-creasing of salt stress concentration. Salt-sensitive germplasm IR29 plant synthesis and accumulation of sucrose and soluble sugar were more than those of salt tolerant germplasms JX99 and Pokkali, however, the growth and development of plants were significantly inhibited. This was due to IR29 plant synthesis and accumulation of sucrose and soluble sugar was partly used to alleviate cell osmotic pressure and anti-physiological recovery, but the other part of the supply of plant growth was insufficient. Slight salt stress could stimulate the activity of SPS and SS to increase accumula- tion of sucrose and soluble sugar, alleviate cell osmotic pressure, and maintain normal vital activities, finally improve the plant's stress resistance. The activity of SS and SPS decreased under moderate and severe salt stress, and sucrose synthesis and accumulation in leaves were reduced, thus, the growth and development of plants were significantly inhibited.%为了探究盐胁迫对水稻的蔗糖合成酶(SS)、磷酸蔗糖合成酶(SPS)活性与糖积累的影响及它们之间的响应机理,选取3份水稻种质材料,在6个NaCl浓度梯度处理下,采用桶栽土培的方法培育至孕穗期,研究了盐胁迫处理对水稻植株外观形态、蔗糖含量、可溶性糖含量、SS活性、SPS活性的影响.结果表明:盐胁迫抑制水稻的生长发育,表现为株高变矮,分蘖数减少,叶面积较小,叶片枯萎等,其抑制作用随盐胁迫浓度提高而增强;盐胁迫下,盐敏感种质IR29植株合成积累的蔗糖和可溶性糖较耐盐种质JX99、Pokkali的多,但其植株生长发育受到的抑制作用更为明显.这是由于IR29植株合成积累的蔗糖和可溶性糖中有一部分用于缓解细胞渗透压参与抗逆生理恢复,而供给植株生长发育部分不足所致.轻度盐胁迫可激发SPS与SS活性增强,分别促进蔗糖、可溶性糖的积累,缓解细胞渗透压力,维持正常生命活动,提高植株的抗逆性;而中度、重度盐胁迫下SS、SPS活性降低,叶片中蔗糖合成与积累降低,表现为植株生长发育受到明显抑制.
