水稻OsNAP基因的功能分析及其在育种价值方面的研究

NAC转录因子是植物特异的转录因子.本研究通过从水稻日本晴(Oryza sativa L.)的基因组中克隆到一个与拟南芥衰老相关的基因AtNAP(Atlg69490)的同源基因OsNAP.OsNAP的ORF为1 179bp,推测其编码蛋白含有392个氨基酸,等电点为8.55,分子质量为42.195ku.为进一步研究OsNAP的功能,利用显性抑制元件SRDX构建其pCAMBIA1304-35S:OsNAP-SRDX表达载体,通过农杆菌浸染方法将其转化水稻中花11品种.T1代转基因植株通过潮霉素、RealtimePCR、和Western blot鉴定,筛选出4个OsNAP高表达的阳性植株.在种子成熟期,观察到T1代转基因4号植株较野生型相比有明显的延缓衰老的表型,其他农艺性状如单株分蘖数、单株总粒数、单穗饱和穗粒数、千粒重、结实率等都优于野生型.实验证明抑制OsNAP基因的表达能够延缓水稻叶片衰老并可以提高产量,具有潜在的育种价值.

Characterization of OsNAP from Oryza sativa L. and Its Application in Molecular Breeding

NAC transcription factor is unique to plant.OsNAP,the homolog of senescence-related gene AtNAP(Atlg69490) was isolated from rice(Oryza sativa L.).The open reading frame(ORF) of OsNAP was 1 179bp in length,which encoded a 392 amino acids sequence with isoelectric point of 8.55 and molecular mass of 42.195ku.In order to explore the function of OsNAP,the SRDX technology(improvement of CRES-T)was used.We construct the pCAMBIA 1304-35S: OsNAP-SRDX expression vector and transfer it into rice zhonghua11 callus by Agrobacterium tumefaciens.After analysis of hygromycin screened,Realtime PCR and Western blot,4 transgenic rice lines was carried on to valuate the function in further research.The T1 transgenic rice line shows significantly senescence delayed phenotype compared with wild type.Further statistical agronomic characters such as number of panicles,number of total spikelets,number of filled spikelets,the mass of 1000 grains,filling rate are better than the wild type.The results suggested that suppressing the expression of OsNAP can delay the senescence of rice leaf and improve the yield and it has potential breeding role in the future.