硫营养对小麦籽粒淀粉合成及相关酶活性的影响

Effects of Sulfur Nutrition on Starch Synthesis and Related Enzymes Activity in Kernels of Wheat

在田间条件下 ,研究了施硫对小麦籽粒淀粉合成及相关酶活性的影响。结果表明 :在 0～ 2 0cm土层土壤有效硫含量为 5 .84mg/kg的地块上施硫不仅提高了小麦籽粒中蔗糖的含量 ,而且催化蔗糖降解代谢的蔗糖合成酶 (SS)活性提高 ,利于籽粒蔗糖的降解。施硫显著提高了灌浆期间籽粒可溶性淀粉合成酶(SSS)活性 ,并使腺苷二磷酸葡萄糖焦磷酸化酶(ADPGPPase)和束缚态淀粉合成酶 (GBSS)活性在灌浆中、后期维持在较高水平 ,对直链和支链淀粉的合成都起促进作用 ,使总淀粉积累增加 ,千粒重提高 ,产量增加。

The effects of sulfur on starch synthesis and related enzymes activity in kernels of wheat were studied in field experiments where the extractable sulfur content in the experimental soil of 0-20 cm soil layer was 5.84 mg/kg. The sucrose content and the activities of sucrose synthase (SS), adenosine diphosphate glucose pyrophosphorylase (ADPGPPase), soluble starch synthase (SSS) and granule bound starch synthase (GBSS) in kernels were examined with HPLC and enzymological methods. It was showed that addition of sulfur not only increased the sucrose content in kernels, but also enhanced SS activity thereby favoring sucrose degradation (Fig.1). Addition of sulfur kept ADPGPPase (Fig.2) higher during the middle and the later kernel filling stages, improved SSS activity during kernel filling and kept GBSS activity higher during the middle and the later kernel filling stages (Fig.3). Amylose and amylopectin synthesis were advanced (Fig.4), total amount of starch accumulated and weight per 1 000 kernels and kernel yield was increased (Table 1) as sulfur was applied. The results demonstrate that sulfur has significant effects in improving kernel starch synthesis capability and kernel weight and thereby increasing kernel yield.