Analysis of Gene Expression for Manganese Superoxide Dismutase (Mn-SOD) and Fructose-1.6-bisphosphate Aldolase (FBA) in Genetic and Physiological Male Sterility Lines of Wheat
Abstract：Manganese superoxide dismutase(Mn-SOD) is an important anti-oxidant enzyme, which bind manganese functions primarily to protect mitochondrial components from superoxide liberated as a normal byproduct of respiration. Fructose-1,6-bisphosphate aldolase(ALD/FBA) plays a critical role in the photosynthesis in plants. The physiological male sterility, induced by chemical hybridize agent, was different with genetic male sterility which caused by it's own genetic background of sterile cytoplasm. The wheat anthers and ovaries of genetic male sterility, normal fertility and physiological male sterility which induced by chemical hybridize agent SQ-1 were collected as materials for RNA extraction.Based on the differential expressed proteins identified by 2-DE technology, the Mn-SOD and FBA protein were significant and were analyzed by Real-time quantitive PCR. Compared to the normal fertility, the Mn-SOD was distinct down-regulated at young spike stage, uninucleate and trinucleate stages in physiological male sterility , while it's enzyme activity was especially higher than that of control at young spike stage and significantly decreased at binucleate stage. For the genetic male sterility, Mn-SOD was down-regulated at young spike and uninucleate stages, and the enzyme activity was increased at young spike stage but declined at binucleate stage. The FBA was up-regulated in both genetic and physiological male sterility lines at the young spike and uninucleate stages compared with the control, accordingly, it's enzyme activity was also fluctuated with the gene expression. Both the two genes were up-regulated in the ovary and anther of two male sterility lines at the trinucleate stage, and highest expressed in the genetic male sterility, but the expression of Mn-SOD in anther of physiological male sterility was lower than that of control. Mn-SOD and FBA genes were tissue-specific expressed in anther and ovary, and the protein abundance was hysteretic to gene expression. The Mn-SOD was over expressed during uninucleate and binucleate stages, which eliminated abundant active oxygen to keep the normal functions of cells. However, the abortion of anthers was also contributed to the decrease of photosynthesis capability, therefore, result in down-regulated expression of FBA.The study of the both enzyme activity and the gene expression level in different development stages among different male sterile lines contributed to the prefound learn about male sterility, and the consistence of this two index indicate a high relationship of male sterile and this two genes.
