高蛋白野生大豆叶片氮代谢物及根瘤GSγ1和Glba表达分析

Comparison of leaf nitrogenous compounds and GSγ1/Glba expressions of nodule between Glycine max and G. soja with high protein content

为明确高蛋白野生大豆籽粒高蛋白形成过程中特有的遗传规律,以高蛋白栽培大豆为对照,对两类材料整个生育期叶片氮同化物相关指标,及根瘤谷氨酰胺合成酶基因(GSγ1)和豆血红蛋白基因(Glba)表达量的差异进行研究。结果表明:两类型大豆间存在明显差异。R3之后,栽培大豆比野生大豆叶片可溶性蛋白含量下降趋势明显。野生大豆叶片GSA在R3之前增长明显,R3之后下降缓慢。整个生育期间野生大豆叶片硝酸还原酶活性都要高于栽培大豆。野生大豆根瘤中GSγ1表达量在R3之前明显高于栽培大豆,R3期之后相反。从V6开始直到成熟,栽培大豆根瘤Glba的表达量都要高于野生大豆。说明野生大豆生育前期氮代谢及各种物质的合成、代谢较旺盛,而且能长时间地保持叶片高的可溶性蛋白含量及硝酸还原酶活性是籽粒高蛋白形成的原因之一。

In order to clarify the formation mechanism of kernel high protein content in Glycine soja, the traits of leaf nitrogenous compounds and GSγ1, Glba expression of nodule in G. soja with high protein content were studied during the whole growth stage of soybean. G. max materials with high protein content were used as control. The resuits showed that there were significant differences between 2 types of soybean. The decreasing of leaf soluble protein content of G. max was sharper than that of G. soja after R3 stage. Glutamine syntheses activity （GSA） of G. soja increased obviously before R3 then decreased slowly after R3. Leaf nitrate reduction activity （NRA） of G. soja was higher than that of G. max during the entire growth period. The expression of GSγ1 in G. soja nodule was significantly higher than that before R3. However, the opposite result was obtained after R3. From V6 to maturity, the expression of Glba in G. max nodule was significantly higher than that in G. soja. All these indicated that the synthesis metabolism of nitrogenous compounds was very active, and the high content of soluble protein in leaf and the high activity of NRA were the other reasons for the formation of high kernel protein.