| Plants are usually subjected to a variety of adverse stresses during their life,which have a very negative impact on the growth and development of plants,and may even lead to death.Plant stress mainly includes biological stress and abiotic stress.Nearly 50%yield loss of the world main crops are related to abiotic stress every year.Transcription factors play an important role in regulating plant adaptation to abiotic stress.In this study,the effect of overexpressing WRKY,MYB,CBF transgenic plants and their wild-type plants under drought,high salt and low temperature stresses were quantitatively compared through meta-analysis.At the same time,the genotypes of 62 maize introgression lines were analyzed by SSR molecular markers and the drought tolerance of maize was identified during seeding stage in order to screen out single segment introgression lines related to maize drought tolerance.The mechanism of plant growth under abiotic stress was discussed in order to provide theoretical basis for cultivation of drought-tolerant,salt-tolerant and low-temperature-tolerant plants.The main results of this study were as follows:1.The effect of overexpressing WRKY in transgenic plants was different from that in wild-type plants under different water stress conditions.Under non-stressedcondition,the relative water content of transgenic plants was significantly higher than that of wild-type plants,and the survival rate of transgenic plants was significantly higher than that of wild-type plants growing in water stressed environment.Under water stress,7 out of 16parameters showed more than 20%changingrate between transgenic and wild type plants,and the survival rate of transgenic plants was increased by 89.8%compared with their wild-type plants.2.The effect of overexpressing MYB in transgenic plants was different from that in wild-type plants under different salt stress conditions.Under non-stressed condition,transgenic plants and wild-type plants showed considerably different only in proline content index,and there was almost no difference in the other characters.Under salt stress,there were significant differences in soluble sugar content,Na~+content,root length and antioxidant enzyme between transgenic plants and wild-type plants.Of the 16 responses,14 had a change rate of more than 20%,and 6 had a change rate of more than 50%.Among them,the survival rate increased the most,to 90.3%.3.The effect of overexpressing CBF in transgenic plants was different from that in wild-type plants under different temperature stress conditions.Under non-stressed condition,the relative conductivity of transgenic plants was significantly different from that of wild-type plants.However,under low temperature stress,there were significant differences in plant survival rate,antioxidant enzyme and proline content,12 of 13response indexes were more than 20%,and 5 indexs have exceed 50%.Among them,the survival rate had the most remarkable change which had reached to 82.9%.4.The study of the moderator which affects the results of the metal-analysis revealed that that some experimental factors(moderators)could affect the effect of transcription factors expression in different degrees,such as treatment medium(solid medium VS liquid medium VS soil),gene donor and recipient species and types(monocot VS dicot)and the length of treatment time and other factors.5.Zea Mays L.cell wall invertase gene Incw1was not only the rate-limiting enzyme in sucrose catabolism,but also played an important role in Zea Mays L.adaptation to abiotic stress.In this study,the mechanism of transcription factors in plant growth regulation under abiotic stress was investigated by means of statistical and experimental methods,and the survival rate can be used as an effective response variable index for plant adaptation to abiotic stress.The results provide a basis for further analysis of the mechanisms of drought tolerance,salt tolerance and low temperature tolerance in plants. |
PDF Full Text Request