Identification Of Stable Transgenic Lines Of Maize Expressing ABP2

Nowadays, natural calamities take place frequently and climatic environment deteriorates gradually, which cause food production crisis.There are a lot of disadvantages of conventional crossbreeding, for this method cost more time and have limitations between species. As a result, genetic engineering seems to be a more valuable tool to reform characteristics of crop in essence.A bZIP transcriptional factor, named ABP2, specifically binding to cis-element ABRE2 of CAT1 promoter, which had been cloned from a cDNA library of 17dpp maize embryos by using yeast hybrid system in our lab. Meanwhile, it has been proved that the tolerance of transgenic Arabidopsis overexpressing ABP2 to abiotic stress is enhanced. The experiments indicate that this factor can reduce ROS amount and increase expressive levels of multiple resistance genes.so ABP2 can improve the resistance capacity of crops.We have obtained the first generation of transgenic maize,whose genome has been rebuilded by Agrobacteriumtumficense.The study establishes the endogenesis ABP2 expressing profiles of Q319 in abiotic stresses, and tries to acquire a series of stable lines of transgenic maize by checking that whether the laber gene Bar integrates into maize genome. The methods include conventional PCR and Basta screening. In addition, we make sure that ABP2 gene is transcripted by Realtime-PCR and Northern blot. On the basis of these work, we design physiological experiment to confirm the resistance of these lines.The main results are as follows:1) The expression of endogenous ABP2 in maize Q319 is improved by low temperature and oxidative stress. Both of the expressive amounts flunctuate within 12 hours with two peaks.2) 4 stable RNAi lines(69-5-3-1/69-1-5/54-17-2-5/47-6-1-4) and 4 over-expressing lines (24-3-4-3/24-3-4-6/1-3-2-1/66-1-2-9)of maize obtained by identifying the self-breeding progenies from initial independent T2 transplants.3) Photosynthesis parameters assayed indicate that the overexpressive lines 24-3-4-6 improve resistance to drought, while RNAi lines 69-5-3-1 and 54-17-2-5 appear to be more impaired than Q319 in drought.