MRNA Differential Expression Of Drought Tolerant Inbred Line Under Drought Conditions In Maize

Maize originates from the tropical zone of high temperature and humidity in Central and Southern America,so that it has poor tolerance to drought.With the aggravation of ecological conditions,drought has become the major limitative factor to maize production in many countries and regions.Significant difference of drought tolerance was found among maize inbred lines. Furthermore, this difference is caused by different morphological, structural, physiological and biochemical mechanisms. All of these mechanisms, however, are phenotypic characters expressed by proteins. Proteins are encoded with mRNA templates of gene transcripts.57 popularized maize inbred lins were evaluated for drought tolerance.The result showed that 81565 was drought tetorant.In this study, 16% PEG-6000 was used for simulant drought treatment to drought tolerant maize inbred line '81565'. DDRT-PCR technique was used to research mRNA differential expression under drought stress and irrigated control. 3 specific fragments (MDl, MD2 and MD3) were found differentially expressed under drought stress. The expression of MDl and MD2 was down-regulated and the expression of MD3 was induced under drought stress. Sequence analysis and homology alignment showed that MDl had 97% similarity with matK in maize chloroplast genome, a gene encoding maturase included in type II intron splicing of RNA transcript; MD2 had 88% similarity with gene PP2C, encoding serine / threonine protein phosphatase type 2C in Sporobolus stapfianus; and MD3 had 81% similarity with rice gene encoding metacaspase, belonging to aspartic acid specific cysteine caspases.