Expression Of Drought Related Genes AtRD28 And AtCBF4 In Tomato

Drought is the major abiotic stress factor affecting plant growth and development, restricting agricultural production.According to statistics,drought brings the losses to agricultural production is almost the sum losses by other stress.To face the increasingly frequent drought disasters,how to save water for agricultural production and how to make the best of large areas of arid and semi-arid land to develop agriculture need badly to be resolved.Traditional breeding methods are time-consuming and low efficiency to improve crops tolerance to drought.With the development of modern molecular biology and biotechnology,people gradually work out the relationship between the plant and drought tolerance on molecular level.Increasing crop drought tolerance by molecular breeding methods will open up a new way for stress tolerance breeding.A large number of research reported that drought-related genes cloned from Arabidopsis thaliana had been transformed into tobacco and other species.These drought-related heterogenous genes expressed in different species can enhance these plants ability to resist stress.In this study,we transformed two genes AtRD28 and AtCBF4 from Arabidopsis into tomato,analysed the drought-tolerance ability of transgenic plants by the target genes overexpressed in tomato,obtained transgenic plants with resistance which would be used as a drought-resistant germplasm for improving drought tolerance in tomato program.The main results are as follows:1.Two drought-related genes of Arabidopsis were cloned in the base of database information of AtRD28(D13254) and AtCBF4(NM124578).Sequencing results show that:the full length of AtRD28 cDNA is 1018 bp,CDS is 858bp which encode 285 amino acids;the AtCBF4 full length cDNA is 769 bp,CDS is 675 bp encoding 224 amino acids.2.The constructed overexpression vectors of AtRD28 and AtCBF4 were transformed into tomato cultivars ZS5 and A53 by the Agrobacterium-mediated transformation ways.3.A total of 78 putative transgenic tomato plants were obtained by Agrobacteriummediated transformation.It included 38 regenerated plants with AtRD28 gene and 40 with AtCBF4 gene.The PCR analysis of the putative transgenic plants showed that the target gene was integrated into the tomato genome.4.The resistance ability to osmotic stress of transgenic plants future generations was determined under 15%PEG(6000) during seed germination period.To find that the transgenic materials germination rate had a significant increase contrast to the control. Under the treatment of 15%of PEG(6000),the germination rates of all transgenic materials were close to or over 2 times than the controls.The germination rote of two lines RD-land RD3-7 from AtRD28 transgenic plants increased over 32.5%and 34.16%,respectively.The AtCBF4 transgenic line CBF-1 increased up to 25%than the control.5.The drought-tolerance ability of transgenic plants in seedling stage was detected.The result showed that young transgenic tomato plants had a notable drought-tolerance ability than the control at the stage of 3 true leaves and one new.After continuous treatment of drought stress 3 times,the transgenic plants survival rate was higher than the control.