甘蔗脱毒健康种苗蔗糖磷酸合成酶基因差异表达分析

摘要

[目的]探究甘蔗脱毒健康种苗中蔗糖磷酸合成酶(SPS)基因表达对产量和糖分积累影响的作用机理,为提高甘蔗产量和蔗糖含量提供理论参考.[方法]以甘蔗品种新台糖22号的脱毒健康种苗和未脱毒种苗(CK)为供试材料,分别在苗期、分蘖期、拔节期和成熟期进行混合取样,包括未成熟叶、成熟叶、幼茎和成熟茎,利用实时荧光定量PCR(qPCR)检测分析对不同类型SPS基因(SPSA、SPSB、SPSC、SPSD1和SPSD2)在不同生长时期不同组织中的表达情况.[结果]不同类型SPS基因在甘蔗脱毒健康种苗不同部位均有表达,SPSD1和SPSD2基因在未成熟叶和成熟叶中表达量差异明显,且与CK间也存在明显差异,SPSA、SPSB、SPSD1和SPSD2基因在脱毒健康种苗1~3茎节中的表达量高于CK.在拔节期10~23茎节中,SPSA基因在脱毒健康种苗中的表达量较CK低,SPSB基因的表达量较CK高,SPSD1和SPSD2基因的表达量与CK无明显差异.在成熟期10~37茎节中,SPSB基因在脱毒健康种苗中的表达量较CK低,SPSA、SPSD1和SPSD2基因的表达量与CK无明显差异.总体上,随茎秆节间成熟度的增加,SPSA、SPSB、SPSD1和SPSD2基因在脱毒健康种苗中的表达量与CK差异逐渐减小.[结论]不同类型SPS基因在甘蔗脱毒健康种苗不同生长时期不同组织中均差异表达,推测甘蔗脱毒处理能促进叶片和未成熟茎节中SPS基因的表达,有利于提高甘蔗产量和蔗糖含量.%[Objective]The regulation mechanism of sucrose phosphate synthetase(SPS) on sucrose accumulation and yield in disease-free sugarcane seedlings was analyzed in order to provide reference for improvement of sugarcane yield and sucrose content.[Method]Ordinary seedlings(CK) and disease-free seedlings of sugarcane cultivar ROC22 were used. The materials,including young leaves,mature leaves,young stems and mature stems,were sampled in mixed manner during seedling stage,tillering stage,elongation stage and mature stage. The expression levels of SPS genes of different types(SPSA,SPSB,SPSC,SPSD1 and SPSD2)at various developmental stages in different tissues were analyzed with real time fluorescence quantitative PCR(qPCR)method.[Result]Different SPS genes were expressed in all sugarcane tissues of disease-free seedlings. The expressions of SPSD1 and SPSD2 were different in young leaves and mature leaves,and the expressions were also obviously different from those in CK. Expressions of SPSA,SPSB,SPSD1 and SPSD2 in 1st-3rd internodes of disease-free seedlings were higher than control. In the 9th-23th internodes at elongation stage,the expression of SPSA in disease-free seedlings was lower than control,but the expression of SPSB in disease-freeseedlings was higher than control and the expressions of SPSD1 and SPSD2 was not significantly different from that in control. Overall,the expressions of SPSA,SPSB,SPSD1 and SPSD2 in disease-free seedlings became closer to those in CK as internodes became more mature.[Conclusion]Although different SPS genes are differentially expressed in tissues of disease-free sugarcane seedlings at different developmental stages,the differential expressions are various. It is predicted that disease-free treatment is able to increase SPS genes expression in leaves and young internodes to improve the sucrose content and sugarcane yield.