RESUMO
Chitinases are important disease-related proteins that play critical roles in plant defense against disease. To investigate the function of chitinases in the resistance of Hami melon to Penicillium infection, the gene encoding chitinases, HmCHT-2, was cloned and RT-PCR was used to measure expression levels of HmCHT-2. When the Hami melon was infected by Penicillium sp after 0, 12, 36, 48, 60, and 72 h. The results showed that comparing to the control group, the time of expression levels reaching to the peak delayed and the expression levels maintained at a significantly high level for a longer time. These results suggest that HmCHT-2 may contribute to the defense of Hami melon against fungal infection.
Assuntos
Quitinases/genética , Cucurbitaceae/genética , Cucurbitaceae/microbiologia , Penicillium , Proteínas de Plantas/genética , Quitinases/metabolismo , Clonagem Molecular , Expressão Gênica , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de TempoRESUMO
Primers were designed according to the Cu/Zn-SOD gene sequences of cloned Cucurbits plants (cucumbers and watermelons) available in NCBI. Total RNA from Hami melon pulp was used as a template. Following RT-PCR amplification, a 403-bp fragment of the Hami melon Cu/Zn-SOD gene was obtained. According to alignment in BLAST and phylogenetic tree analysis, the cloned gene fragment was confirmed to be the Hami melon Cu/Zn-SOD gene sequence. Real-time fluorescence quantitative expression analysis indicated that there were differences in the expression of SOD mRNA expression before and after infection by blue mold. mRNA expression was maximal 24-h after infection, indicating that the product of the SOD gene plays an important role in the rotting and degeneration of Hami melons as a consequence of bacterial infection during the preservation period.
Assuntos
Cucumis sativus/genética , Cucurbitaceae/genética , Filogenia , Superóxido Dismutase/genética , Sequência de Bases , Clonagem Molecular , Cucumis sativus/microbiologia , Cucurbitaceae/microbiologia , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Alinhamento de Sequência , Superóxido Dismutase/biossínteseRESUMO
The effect of the antagonistic yeast XL-1 on resistance-associated enzyme activities in postharvest cantaloupe was studied by inoculating the antagonistic yeast XL-1. Cantaloupes were sterilized, dried in air, and soaked in antagonistic yeast treatment liquid for 30 s. After drying in air, the cantaloupe was stored at room temperature (2°-5°C). The activities of resistance-associated enzymes in cantaloupe like polyphenol oxidase, ß-1,3-glucanase, peroxidase, and superoxide dismutase were measured every 7 days. Our results indicated that the antagonistic yeast XL-1 significantly improved the activity of ß-1,3-glucanase and chitinase to promote the disease resistance of postharvest cantaloupe.