Functional Genomics Laboratory, Centre of Biotechnology, Siksha O Anusandhan University, Bhubaneswar, Odisha, India.
Functional Genomics Laboratory, Centre of Biotechnology, Siksha O Anusandhan University, Bhubaneswar, Odisha, India.
Plant Sci. 2017 Apr;257:9-21. doi: 10.1016/j.plantsci.2017.01.007. Epub 2017 Jan 19.
The basal plate rot fungus, Fusarium oxysporum f. sp. cepae (FOC), is the most devastating pathogen posing a serious threat to garlic (Allium sativum L.) production worldwide. MicroRNAs (miRNAs) are key modulators of gene expression related to development and defense responses in eukaryotes. However, the miRNA species associated with garlic immunity against FOC are yet to be explored. In the present study, a small RNA library developed from FOC infected resistant garlic line was sequenced to identify immune responsive miRNAs. Forty-five miRNAs representing 39 conserved and six novel sequences responsive to FOC were detected. qRT-PCR analyses further classified them into three classes based on their expression patterns in susceptible line CBT-As11 and in the resistant line CBT-As153. North-blot analyses of six selective miRNAs confirmed the qRT-PCR results. Expression studies on a selective set of target genes revealed a negative correlation with the complementary miRNAs. Furthermore, transgenic garlic plant overexpresing miR164a, miR168a and miR393 showed enhanced resistance to FOC, as revealed by decreased fungal growth and up-regulated expression of defense-responsive genes. These results indicate that multiple miRNAs are involved in garlic immunity against FOC and that the overexpression of miR164a, miR168a and miR393 can augment garlic resistance to Fusarium basal rot infection.
基础盘腐菌，尖孢镰刀菌茄腐专化型（FOC），是对全世界大蒜（Allium sativum L.）生产构成严重威胁的最具破坏性病原体。MicroRNAs（miRNAs）是真核生物发育和防御反应相关基因表达的关键调控因子。然而，与大蒜抵御 FOC 相关的 miRNA 种类尚未得到探索。在本研究中，从抗 FOC 感染的大蒜抗性系中构建的小 RNA 文库进行测序，以鉴定免疫响应 miRNA。检测到 45 个 miRNA，代表 39 个保守序列和 6 个新序列对 FOC 有响应。qRT-PCR 分析根据其在易感系 CBT-As11 和抗性系 CBT-As153 中的表达模式将它们进一步分为三类。对六个选择性 miRNA 的 Northern blot 分析证实了 qRT-PCR 结果。对一组选择性靶基因的表达研究表明，与互补 miRNA 呈负相关。此外，过表达 miR164a、miR168a 和 miR393 的大蒜转基因植株对 FOC 的抗性增强，表现为真菌生长减少和防御反应基因的上调表达。这些结果表明，多种 miRNAs 参与了大蒜对 FOC 的免疫反应，并且过表达 miR164a、miR168a 和 miR393 可以增强大蒜对镰刀菌基础腐烂感染的抗性。
