| Cytokinins are important plant hormones that play an important role in plant growth and development.The cytokinin oxidase/dehydrogenase (CKX) degrades CKs irreversibly by removing their N6-substitutedisoprene chain to produce an adenine and a corresponding unsaturated aldehyde-3-methyl-2-butenal. TheCKX enzyme is thought to play an essential role in controlling the local CK level and subsequentlycontributing to the regulation of cytokinin-dependent processes in planta. The new cDNA sequence ofZmCKX1was cloned by RT-PCR method from maize inbred line Zheng58, according to the nucleotidesequence of OsCKX2in GenBank. The levels of ZmCKX1transcript accumulation were measured invarious periods of tassel and ear after pollination in the different maize strains by using the Real-timeFluorescence quantitative PCR. At the same time, The ZmCKX1gene over-expression vector and RNAinterference vector were trans-formated into the maize immature embryo by Agrobacrerium tumefaeiems.The main conclusions of this study were as following:1. The open reading frame of ZmCKX1is1608bases in length and encodes a predicted protein of535amino acids, which protein molecular weigh is57kＤ and pI is5.22. The alignment analysis of cDNAsequence showed that ZmCKX1shared69%and49%identity with the TaCKX1and AtCKX, respectively.2. The hightest level of ZmCKX1were detected in the ear of30days after pollination(30d), which isabout5times and50times more than that of10d,0d, respectively. ZmCKX1expression was found to benegatively correlated with ear tissue growth activity and hybrid seedling vigor. Regardless of whetherZmCKX1gene directly contribute to, or merely mimic, heterosis, they may aid generation of morevigorous and productive crop plants.3. Using PCR method detect the regenerated plants. The results shows that ZmCKX1gene has insertedinto the plant genomes and30strains are positive plant with ZmCKX1gene from the500maize immatureembryos. |
PDF Full Text Request