硝普钠对圣女果种子萌发至幼苗期碳氮代谢及关键酶活性的影响

Effect of Sodium Nitroprussiate on the Metabolites and Key Enzyme Activities of Carbon-Nitrogen Metabolism from Seed Germination to Seedling Period of Cherry Tomatoes

为了探明硝普钠对圣女果种子萌发及幼苗生长的调控机制,以圣女果品种朱云为试验材料,研究不同浓度硝普钠处理对其碳氮代谢及关键酶活性的影响。结果表明,圣女果种子萌发至幼苗期,淀粉、总氮含量逐渐下降,可溶性糖、还原糖、蔗糖和可溶性蛋白质含量呈先上升后下降的趋势,游离氨基酸含量逐渐上升;硝普钠处理的淀粉、蔗糖及游离氨基酸含量均高于蒸馏水处理(CK);圣女果种子萌发至幼苗期,淀粉酶、蔗糖磷酸合成酶(SPS)和谷氨酰胺合成酶(GS)活性呈下降趋势,硝酸还原酶(NR)和谷氨酸合成酶(GOGAT)活性呈先上升后下降的趋势;CK和0.25 mmol/L硝普钠处理的蔗糖合成酶(SS)活性呈下降趋势,0.50、1.00 mmol/L硝普钠处理SS活性呈先上升后下降的趋势,且硝普钠处理增强了淀粉酶活性;各处理碳含量逐渐下降,碳氮比除CK呈先上升后下降外,其他硝普钠处理均呈下降趋势;此外,硝普钠处理对种子发芽势和发芽率影响不显著,但显著增加了幼苗生物量、根长和苗高。可见,硝普钠处理可影响淀粉的转化和糖的积累,延缓总氮和萌动期前可溶性蛋白质的分解,加速游离氨基酸的积累,促进种子萌发和幼苗生长,其中以0.50 mmol/L效果最佳。

The purpose of this paper was to elucidate the regulating mechanism of sodium nitroprussiate on seed germination and seedling growth of cherry tomatoes. After treated by different concentration of sodium nitroprusside, the effect on the metabolites and key enzyme activities of carbon -nitrogen metabolism of cherry tomatoes cultivar Zhuyun as materials were investigated. The results showed that from seed germination to seedling period, the contents of starch, total nitrogen decreased, but the contents of soluble sugar, reducing sugar, sucrose and soluble protein increased firstly and then decreased; free amino acids content increased gradually. Sodium nitroprusside made the contents of starch, sucrose and free amino acids higher than CK. Seed germination to seedling stage in cherry tomatoes, the activities of amylase,glutamine synthetase （ GS ） and sucrose phosphate synthase （ SPS ） decreased ; the activities of nitrate reductase （ NR） and glutamate synthase （ GOGAT） were first increased and then decreased; CK sucrose synthase（SS） activity decreased. The sucrose synthase（SS） activity decreased with the treatment of CK and 0. 25 mmol/L sodium nitroprusside,and the trend was first increased and then decreased after treatment at 0.50,1.00 mmol/L sodium nitroprusside. Sodium nitroprusside treatment increased amylase activity; carbon-nitrogen ratio of CK increased first and then decreased, while the others tended to decrease. In addition, sodium nitroprusside on seed germination potential and germination rate were not affected, but significantly increased biomass accumulation, root length and height of the seedling. These data suggest that sodium nitroprusside can influence the conversion of starch and sugar accumulation, delay the decomposition of total nitrogen and soluble protein, accelerate the accumulation of free amino acids, promote the seed germination and seedling growth, of which 0. 50 mmol/L has the best effect.