Influence Of ACC Oxidase 1 Co-suppression On The Expression Of Fruit Ripening And Diseases Related Genes

This study aims at researching the effect of ACC oxidase 1 co-suppression on the expression of fruit ripening related genes, pathogenesis-related genes and on the effect of different environmental stresses on the ACC oxidase 1. We used the ACC oxidase co-suppression tomato plants (T4B-11 and V1187), wild-type tomato plants (WT), the ethylene-responding mutants Nr and rin as the material. Then the specific ACC oxidase 1 gene, ACC oxidase 3 gene, EBF1 gene, PR1 gene, PR5 gene and NP24 genes of tomato were cloned and prepared for probes which were used to hybridize with total RNAs. The mail work and conclusions as follows:(1) The cloning of specific gene fragments of tomato fruit ripening related genes and pathogenesis-related genes:Gene specific fragments for LeACO1, LeACO3, LeEBF1, PR5, PR1 and NP24 were amplified by PCR or RT-PCR using designed primers based on the gene sequences in the NCBI database (GeneBank numbers: X58273, Z54199,DQ307488,AJ277064,X71592 and AF093743).(2) Expression of ripening related genes in LeACO1 co-suppression tomato fruits:Total RNA was extracted from fruits of WT, V1187 and T4B-11-11 in the four different ripe stages, which were IMG, MG, Breaker and Breaker+4. Hybridized with LeACO1, LeACO3, LeEBF1, PR5 and NP24 gene fragments marked byα-32P-dCTP. The results show that LeACO1 co-suppression strongly inhibits the endogenesis ethylene biosynthesis, fruit mature and consenescence and the expression of LeEBF1. The LeACO1 gene is likely to be the main regulative factor in the process of tomato fruit ripening. The expression of LeACO1 gene was restrained while interdicted the expression of LeACO3.(3) Pathogenesis related genes expression in LeACO1 co-suppression tomato fruitsTwenty micrograms of total RNA from the fruit pericarp material of non-transformed wild type control and ACO1 co-suppression plants T4B-11 was blotted and hybridized. The probes were the gene segments of PR1, PR5 and NP24 marked byα-32P-dCTP. The results show that the expression of PR gene is induced by endogenesis ethylene.(4) Effect of environmental stresses and ethylene on the expression of ACC oxidase 1 Gene...