Photosynthetic Characteristics And Chloroplast Proteins Analysis Of Leaf Color Mutants Of Biao 810S

The leaf color mutant is an ideal material which is studied for the photosynthesis system structure, the function and the regulative mechanism. It also has very wide application in hybrid rice as the trait marker. It is important to study its physiological biochemistry characteristic, which has academic significance and potenial application value.Biao 810S is a yellow leaf color mutant which is discovered from dual-purpose genie male sterile line 810S by Huaihua Vocational and Technical College. Except the marked trait, Biao 810S's shape and physiological characteristics are basically the same with 810S's. Some studies indicated that Biao 810S's marked trait is controlled by one pair of recessive genes, but not influenced by environmental factors. So this trait can be considered as the marked trait of female parent in the process of hybrid breeding, for the benefit of preserving female parent and remove the crossbreed. It can also be used to detect proportion of female parent seeds in the hybrid seeds. This article perform research on the Biao 810S's photosynthesis characteristics and chloroplast proteins, in order to strength the theoretic understanding and facilitate the application of this marked trait.We have performed a comparative study of the pigment content, net photosynthetic rate, dark respiration rate, chloroplast proteins and hybrid combination photosynthetic rate between a leaf color mutant (Biao810S) and thermo-sensitive genic male-sterile (810S).The results are summarized as follows: 1. Through the comparison of the photosynthesis pigment content in tillering stage, Biao 810S's chlorophyll a(1.27mg.g^-1FW), b(0.53 mg.g^-1FW) and carrot(0.43 mg.g^-1FW) content are about 50% lower than that of 810S (as control). Both ratios of chlorophyll a/b and chlorophyll/carotenoid have no significant differences between these two species.2. With the rise of temperature, the net photosynthetic rates of both Biao 810S and 810S show the rise tendency, reaching the maximum rates at 30℃, which are 28.31μmolCO₂·m^-2·s^-1 and 22.09μmolCO₂·m^-2·s^-1 respectively. While at 35℃, the net photosynthetic rates of Biao 810S and 810S fall to 25.52μmolCO₂·m^-2·s^-1 and 21.99μmolCO₂·m^-2·s^-1respectively. However, the net photosynthetic rates of these species have no significant differences at 20℃, but the net photosynthetic rate of Biao 810S is higher than that of 810S with the temperature rise.3. The dark respiration rates of Biao 810S and 810S increase along with the temperature rise. But Biao 810S dark respiration rate are all higher than that of 810S at 4 temperature(20℃, 25℃, 30℃, 35℃).4. The height and dry weight of Biao 810S are slightly lower than that of 810S at different growth stages. While tiller capacity, plantleaf type, caulis sturdiness degree and duration period are the same with 810S.5. No significant difference of net photosynthetic rate, height and dry weight are detected in F₁ generation of both Biao 810S and 810S with the same male parent.6. The proteomics technology now becomes a powerful tool for the investigation in the present study. The 2-DE chloroplast protein maps of a leaf color mutant (Biao810S) and 810S are obtained by optimizing crucial factors and procedures such as sample treatment, electrophoresis parameters, and gel concentration. Several modified procedures are used in 2-DE, such as proper lysis solution to treating samples, choosing moderate amount of sample, using pre-cast immobilized linear dry strips for the first dimensional electrophoresis, 15% separation gel and 4.8% concentrating gel used in the SDS-PAGE electrophoresis. The 2-DE chloroplast protein maps of Biao810S and 810S are compared. We identify 14 protein spots which show significant and reproducible variations, and then we search their molecular, function and biological process in the database. Most of the difference proteins are ATPase, the light system related proteins and so on.