Coparative Dynamic Analyses Of Plastid Pigment Biosynthesis Of Flue-cured Tobacco Growing In Yunnan And Hennan

In order to clarify the effects of different ecological regions on the changes of tobacco plastid pigment content, the flue-cured tobacco cultivar K326 was grown in Pingdingshan, Henan and Yuxi , Yunnan, respectively. The differences of plastid pigment and its degradation products content as well as chloroplast ultrastructure between Yunnan and Henan tobacco were researched. The chip hybridization was used to clarify the differentially expressed genes in the leaves at physiological maturity stage which planted in the two different regions. According to the results of the chip hybridization, expression levels of critical plastid pigment synthesis genes were confirmed by Reverse Transcription-Polymerase Chain Reaction (RT-PCR).The main results are followed as listed:1. Except neoxanthin, other carotenoids content in Yunnan tobacco were higher than that in Henan tobacco. However, in early stage of leaf development, the content ofβ-carotene in Henan tobacco was close to or higher than that in Yunnan tobacco, but it was significantly decreased in the later stages. The comparison of the chlorophyll component contents showed that: Before leaf age 50 d the content of chlorophyll a in Henan tobacco was higher than that in Yunnan tobacco. The content of chlorophyll b in Yunnan tobacco was always higher than that in Henan tobacco except that on the leaf age 30 d.2. Comparison between Yunan and Henan tobacco on the RT-PCR results of the critical plastid pigment synthesis genes showed that: The pigment synthesis gene expression intensity in Yunnan tobacco leaves was higher than that in the corresponding periods of Henan, especially in the later stage, the expression of pigment synthesis genes sharply decreased in Henan tobacco even could hardly to be detected. 3. Results of researches on the tobacco leaves’ultra-structure showed that Yunnan tobacco leaves had more starch grains in the chloroplast compared with that in Henan; But on 30 d of leaf age, the chloroplast in Henan tobacco contained more starch grains than that in Yunnan. After the 50 d of leaf age, chloroplast starch grains in Yunnan tobacco increased and came to be more larger than that in Henan tobacco and till harvest time. Results indicated that the degradation rate of chloroplast in Yunnan tobacco was much higher than that in Henan tobacco.4. Microarray hybridization results showed 250 genes were high-expressed in Yunnan tobacco. Among them 13 genes which participate in photosynthesis and starch metabolism were selected. And 10 genes participated in photosynthesis, which encoding the genes in photosystem I,Ⅱsystem and the subunit of photosystem I. Two genes which involved in the synthesis of starch and sucrose were starch synthase and the starch branching enzyme. One gene involved in sucrose synthesis is enzyme of fructose phosphate acetal.