四种油料作物中的细菌型PEPC基因的鉴定及在发育种子中的表达

鉴定和获取了四种油料作物（油菜、大豆、花生和芝麻）中的细菌型PEPC基因，分析了所编码蛋白的保守结构域（BOX I-IV）和蛋白作用功能位点。基因包括甘蓝型油菜的Bna10093361、Bna1009749和Bna10093360，大豆的Glyma10g34970.1, Glyma01g22840.1和Glyma02g14500.1，芝麻的SIN1018296和花生的AhPPC5。这8个基因含有19～21个内含子，内部插入一个约350～600bp的高度变异区，编码的蛋白在C端形成R/KNTG结构域，在N端缺乏磷酸化作用位点。在种子发育的不同时期，油菜中仅Bna10093360表达，但其表达量不到油菜BnActin表达量的0.1%；大豆中Glyma10g34970.1表达量最高（接近大豆GlymaActin的2%），Glyma02g14500.1次之；花生AhPPC5表达量为花生AhActin的32%～175%，在种子不同发育时期表达量为早期>中期>晚期；芝麻SIN1018296表达量为芝麻SINActin的3%～18%，在种子发育时期的表达趋势和花生AhPPC5相似。8个基因种子中的表达模式差异明显，说明细菌型PEPC基因可能存在着广泛的功能分化。  

Bacterial-type PEPC genes identification and expression in developing seeds from four oil crops

 Bacterial-type PEPC genes were cloned from four oil crops (rape, soybean, peanut and sesame). Their sequences of conserved domains (BOX I to BOX IV) and PEPC activity sites were characterized. The genes included Bna10093361, Bna1009749 and Bna10093360 from Brassica napus, Glyma10g34970.1, Glyma01g22840.1 and Glyma02g14500.1 from Glycine max, SIN1018296 from Sesamum indicum, AhPPC5 from Arachis hypogaea. The 8 genes were commonly composed of 19 to 21 introns, and contained one unique and highly divergent insertion of about 356 to 600bp. PEPC sequences had R/KNTG in C-terminal tetrapeptide, but lacked the phosphorylation motif at N terminus. Results from RT-qPCR showed that Bna10093360 expressed with less than 0.1% of rapeseed BnaActin, Glyma10g34970.1 and Glyma02g14500.1 expressed with less than 2% of soybean GlymaActin. AhPPC5 expressed 32% to 175% of peanut AhActin, and SIN1018296 expressed 3% to 18% of sesame SINActin. The expression trends of AhPPC5 and SIN1018296 were higher at early seed developing stage and then decreased. Results indicated that the bacterial-type PEPC gene functions were widely differentiated.