超表达杨树RPEase基因促进了拟南芥的生长发育

卡尔文循环是光合作用CO2同化的重要途径,在植物生长发育过程中起着重要作用。磷酸核酮糖3-差向异构酶(RPEase:EC 5.1.3.1)是卡尔文循环再生阶段的一种重要酶类。本文从速生欧美杂交黑杨NE-19中克隆得到RPEase基因,构建植物表达载体,利用农杆菌花序侵染法转化野生型和突变体拟南芥,通过普通PCR检测和绿色荧光蛋白(GFP)观测进一步鉴定得到CaMV35S:PdRPE:GFP超表达株系,然后对野生型、超表达株系、突变体和回补株系的生理指标进行测定。结果显示,超表达株系RPEase活性显著升高(P<0.05)。在正常浇水的生长条件下,超表达株系相比于其他3个株系(野生型、突变体、回补株系),气孔数目减少,气孔变大,提高了植物的水分利用效率以及净光合速率,使得超表达株系有更好的生长优势,积累更多的淀粉。在10d的短期干旱条件下,超表达株系的净光合速率和水分利用效率依然显著高于其他3个株系(P<0.01)。因此,研究表明超表达RPEase基因会提高植物生物量的积累以及对短期干旱的抵抗能力。 

Over-expression of RPEase gene promotes the growth and development of Arabidopsis thaliana

The Calvin cycle is an irreplaceable pathway for photosynthetic organisms to assimilate CO2 from the air and therefore plays a crucial role in plant growth and development. The ribulose-phosphate 3-epimerase (RPEase:EC 5. 1. 3. 1) is one of the integral enzymes in the Calvin cycle regeneration phase. In our study PdRPE gene was cloned from fast-growing hybrid poplar NE-19 ( Populus nigra í ( Populus deltoids í Populus nigra) ) , and then PdRPE was transformed into Arabidopsis thaliana by the floral dip method. Using PCR and Green Fluorescent Protein ( GFP ) detection methods, we obtained the CaMV35S:PdRPE:GFP transgenic plants. Then we validated the growth status and physiological indexes of wild type (Col-0), overexpressing (OxPdRPE), mutant (rpe) and complementary (rpe/PdRPE) lines. The results indicated that in overexpressing lines RPEase activity increased significantly ( P <0. 05). When well-watered, the overexpressing lines had lower leaf stomatal density, larger stomatal size, improved water use efficiency and higher net photosynthetic rate, showing a better growth condition and more starch accumulation. When exposed to 10 days of short-term drought, the net photosynthetic rate and water use efficiency of overexpressing lines were still significantly higher than those of the other three strains (P<0. 01). Therefore, we reach the conclusion that over-expression of RPEase gene can promote the plant growth and development and enhance the resistance of short-duration drought in Arabidopsis thaliana.