甘蔗根系构型及磷转运子ScPht1在磷高效吸收转运中的功能研究

Sugarcane (Saccharum officinarum), is the most important sugar crop and fuel crop in China. Most agricultural land of sugarcane main producing areas is deficient in phosphorus (P) in China, which has serious effects on improving cane yield and quality. Considerable genotypic variation exists among different cultivars in P uptake and transport. It has been reported that both root system regulation and P transporter Pht1 family play main roles in improving P uptake and transport under P deficiency in rice plant. P-efficient cultivar YR06-8362 and P-inefficient cultivar Co285 will be used in this study: 1) 3D reconstruction & dynamic modeling system and CI-600 dynamic observation system will be used for investigating the relationship between root morphology, architecture and P efficiency; 2) ScPht1 family genes will be cloned and their expression patterns and positions will also be investigated. Moreover, yeast mutant MB192 and Oocytes will be used for identifying and validating the functions of the genes which expressed significantly differently between P efficient and inefficient cultivars in P uptake and transport. Based on above, some members closely related to P uptake and transport of ScPht1 family will be gained. 3) One or two genes of the genes more closely related to P uptake and transport will be further selected for functional charactering via GUS&GFP expression and transformation of Arabidopsis thaliana. The results of this project will dissect the molecular basis of P efficient uptake and transport , and provide theoretical bases for genetically improvement in P efficiency in sugarcane.

甘蔗是我国最主要的糖料作物及能源作物，主产区土壤普遍缺磷，严重制约产量和品质的提高。甘蔗不同基因型磷的吸收及转运存在显著差异。研究表明，低磷胁迫下，根系调节及根中磷转运子Pht1基因家族在水稻中主要负责提高对磷的吸收和转运。本项目将以磷高效品种云瑞06-8362和低效品种Co285为材料，利用3D根系扫描系统和CI-600根系生长动态观测系统明确不同品种根系形态构型的差异及与磷效率间的关系；克隆甘蔗磷转运基因（ScPht1s），分析基因时空表达模式，进一步通过酵母突变体MB192和卵母细胞表达系统来鉴定和验证显著差异表达基因的磷吸收功能特征，最后获得与磷高效吸收转运密切相关的基因；对选出的1-2个与磷高效吸收转运最密切相关的关键基因进行GUS、GFP和拟南芥转化验证其功能。通过此研究，有望从分子水平上解析甘蔗磷高效吸收转运机制，可为甘蔗磷高效的遗传改良提供基础。