百合鳞茎发育过程中淀粉合成相关酶基因的克隆及表达分析

该研究通过同源克隆技术克隆腺苷二磷酸葡萄糖焦磷酸化酶(AGPase)、颗粒结合淀粉合酶(GBSS)和可溶性淀粉合酶(SSS) 3类百合淀粉合成关键酶基因,分析这三类淀粉合成关键酶基因的表达变化,测定百合鳞茎膨大发育中淀粉含量变化。结果表明:(1) AGPase具有GlgC家族蛋白PLN02241蛋白结构特征及cl11394家族蛋白ADP_Glucose_PP与NTP_transferase结构域,获登录号KP751443; GBSS与SSS具有cl10013家族蛋白Glyco_transf_5,GT1_Glycogen_synthase_DULL1_like结构域,获登录号分别为KP751444、KP751445。(2)百合鳞茎形成与膨大发育过程中,淀粉含量呈现递增趋势,鳞茎盘开始分化茎杆时其淀粉含量最高,达到44.52%。鳞茎与叶片部位的三个淀粉合成相关酶基因表达量均逐渐增加;在鳞茎膨大后茎杆分化阶段,三个淀粉合成相关酶基因表达量达到最高,AGPase、GBSS、SSS在鳞片中的表达量分别为10.79,6.92和5.12,叶片中的表达量分别为6.79,5.22和4.41,鳞片中的表达量大幅度高于叶片;淀粉合成相关酶基因的表达量变化与淀粉含量、鳞茎的膨大发育成正相关。这为鳞茎的繁殖生产提供了可通过调节淀粉合成关键酶基因表达促进百合鳞茎膨大发育的思路。

Cloning of starch synthesis-related enzyme gene and its expression analysis in process of bulblet development of Lilium

The key enzyme genes of lily starch synthesis, ADP glucose pyrophosphorylase(AGPase), granule binding starch synthase(GBSS)and soluble starch synthase(SSS), were cloned by homologous cloning, and the bioinformatics analysis was performed. The bulblets and leaves of lily during the four stages of bulblet swelling development were used to determine the starch content in bulblets at different stages, and the expression of the key genes encoding starch synthesis-related enzymes in the process of bulblet swelling development were analyzed using fluorescence quantitative PCR. The results were as follows:(1)AGPase had PLN02241 protein domain belonging to GlgC family protein and ADP_Glucose_PP and NTP_transferase domain belonging to cl11394 family protein. The accession number of AGPase gene was KP751443. GBSS and SSS had Glyco_transf_5, GT1_Glycogen_synthase_DULL1_like conserved domain belonging to cl10013 family protein. The accession numbers of GBSS and SSS genes were KP751445 and KP751444, respectively.(2)The starch content showed an increasing trend in the process of the formation and development of lily bulblet swelling. The starch content was up to 44.52% at the stem differentiation stage after bulblet swelling, which was the highest. The three starch synthesis-related genes were up-regulated gradually in bulblets and leaves. The expression of these three starch synthesis-related genes were up to the peak at the stem differentiation stage after bulblet swelling. The expression of AGPase, GBSS and SSS were 10.79, 6.92 and 5.12 in bulblet, and were 6.79, 5.22 and 4.41 in leaves, respectively. The genes expression were much higher in bulblets than in leaves. There was a positive correlation between the starch synthesis-related gene expression and the content of starch and bulblet swelling. The finding provides a reference for propagation production of lily bulblet, by which the expression of key synthesis-related genes can be regulated to promote the swelling development of lily bulblet.