《植物生理学报》 2017, 53(5): 857-864
摘 要：果糖-1,6-二磷酸醛缩酶(FBA)是糖酵解、糖异生、磷酸戊糖途径及光合作用过程的关键酶。本研究利用荧光定量分析研究IbFBA5基因在甘薯不同组织及不同生长时期的表达及与叶片和贮藏根中碳水化合物积累的关系。结果表明, IbFBA5具有组织表达特异性, 在甘薯‘徐781’叶片中表达量最高, 其次是地下部(牛蒡根、储藏根和纤维根), 叶柄、茎和花中表达量较低; 甘薯储藏根初始膨大期至膨大盛期, IbFBA5在‘徐薯18’叶片中表达量均极显著高于在‘徐781’中的表达量; 而在储藏根初始膨大期和膨大盛期, 该基因在‘徐781’储藏根中的表达量均显著或极显著高于‘徐薯18’中的表达量。可溶性糖和淀粉含量分析表明, 甘薯初始膨大期至膨大中期, 叶片和储藏根中果糖和葡萄糖的含量均极显著提高, 储藏根中淀粉含量也极显著提高, 然而储藏根中的蔗糖含量及叶片中淀粉含量极显著降低。甘薯叶片和储藏根中IbFBA5的表达模式分别与不同时期叶片中淀粉的含量变化和储藏根中果糖及葡萄糖的含量变化趋势具有一致性。
关键词：甘薯; 果糖-1,6-二磷酸醛缩酶; 时空表达; 可溶性糖; 淀粉
Corresponding author: LI Qiang; E-mail: email@example.com
Abstract:Fructose-1,6-bisphosphate aldolase (FBA) is a key enzyme in the pathway of glycolysis, gluconeogenesis, pentose phosphate and photosynthesis. The expression of IbFBA5 in different tissues and different growth periods were carried out by qRT-PCR analysis in this paper. We also analyzed the relationship among the gene expression levels and carbohydrate accumulations in leaves and storage roots. The results indicated that the expressions of IbFBA5 were specific in different tissues, which showed highest expression in leaves and also high expression in roots, but low expression in petiole, stems and flowers. The gene expression levels were discrepant in leaves and roots of different genotypes, ‘Xushu18’ and ‘Xu781’, respectively. The expression levels were significantly higher in the leaves of ‘Xushu 18’ than that of ‘Xu781’ from initial expansion stage to peak expansion stage of storage roots. The expression levels were also significantly higher in the storage roots of ‘Xu781’ than that of ‘Xu18’ at initial period and peak period of expansion respectively. The contents of fructose and glucose were increased obviously from initianl period to medium period in leaves and storage roots as well as the starch contents in storage roots. On the contrary, the sugar contents in storage roots and starch contents in leaves were depressed sharply at this period. We found that the expression patterns of IbFBA5 had consistency with the trends of starch contents in leaves and fructose and glucose contents in storage roots respectively.
Key words: sweetpotato (Ipomoea batatas); FBA; spatiotemporal expression; soluble sugar; starch
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