Ghag Siddhesh B, Shekhawat Upendra K S, Ganapathi Thumballi R
Plant Cell Culture Technology Section, Nuclear Agriculture & Biotechnology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India.
Mol Biol Rep. 2014 Dec;41(12):7929-35. doi: 10.1007/s11033-014-3687-3. Epub 2014 Aug 27.
Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense (Foc), is counted among the most destructive diseases of crop plants in India. In the absence of any credible control measure to manage this disease, development of resistant cultivars is the best option. Somaclonal variations arising out of long term in vitro culture of plant tissues is an important source of genetic variability and the selection of somaclones having desired characteristics is a promising strategy to develop plants with improved characters. In the present study, we isolated a group of somaclonal variants of banana cv. Rasthali which showed efficient resistance towards Foc race 1 infection in repeated bioassays. cDNA-RAPD methodology using 96 decamer primers was used to characterize these somaclonal variants. Among the four differentially amplified bands obtained, one mapping to the coding region of a lipoxygenase gene was confirmed to be down regulated in the somaclones as compared to controls by real-time quantitative RT-PCR. Our results correlated well with earlier studies with lipoxygenase mutants in maize wherein reduced expression of lipoxygenase led to enhanced resistance towards Fusarium infection.
香蕉枯萎病由尖孢镰刀菌古巴专化型（Foc）引起，是印度农作物中最具毁灭性的病害之一。由于缺乏有效的防治措施，培育抗病品种是最佳选择。植物组织长期离体培养产生的体细胞无性系变异是遗传变异的重要来源，选择具有理想特性的体细胞无性系是培育优良性状植株的一种有前景的策略。在本研究中，我们分离出一组香蕉品种Rasthali的体细胞无性系变异体，在重复的生物测定中，它们对Foc 1号生理小种感染表现出高效抗性。使用96个十聚体引物的cDNA-RAPD方法对这些体细胞无性系变异体进行了表征。在获得的四个差异扩增条带中，通过实时定量RT-PCR证实，与对照相比，其中一个定位于脂氧合酶基因编码区的条带在体细胞无性系中表达下调。我们的结果与早期对玉米脂氧合酶突变体的研究结果高度相关，在该研究中，脂氧合酶表达降低导致对镰刀菌感染的抗性增强。
