水稻具有Jumonji C結構域的組蛋白去甲基化酶基因家族的功能性分析

Functional characterization of the Jumonji C domain-containing histone demethylase gene family in rice

陳奕伯(I-Po Chen)

指導教授 ： 洪傳揚

國立臺灣大學/生物資源暨農學院/農業化學研究所/碩士(2022年)

https://doi.org/10.6342/NTU202202889

摘要

組蛋白去甲基化酶可以透過降低組蛋白N端胺基酸的甲基化狀態，影響染色質的凝集狀態，進而影響基因表達。組蛋白去甲基化酶對植物生長發育影響的研究，大部分集中在阿拉伯芥，水稻的研究相當有限，因此本研究針對功能仍未知、屬於KDM3基因群中具有Jumonji C ( JmjC ) 結構域的五個組蛋白去甲基化酶基因 ( OsJMJ715、OsJMJ716、OsJMJ718、OsJMJ719和OsJMJ720 ) 進行分子特性及基因功能分析。分析水稻幼苗在不同環境逆境下，五個基因在根部和地上部表現結果顯示，缺水和鹽分逆境會顯著誘導OsJMJ715、OsJMJ716和OsJMJ718在根部和地上部表現；40°C高溫處理會顯著誘導五個基因在根部和地上部表現；4°C低溫會誘導五個基因在根部顯著表現，但是抑制在地上部的表現。分析T-DNA插入突變株 ( jmj716、jmj718和jmj719 ) 和CRISPR/Cas9基因編輯突變株 ( jmj715和jmj720 ) 外表性狀結果顯示，jmj716突變株發芽後無法生長，jmj718出現株高矮化外表型，jmj715、jmj719和jmj720突變株在外表型上則未出現與野生型明顯不同。這些結果顯示水稻JmjC結構域基因具有不同的環境逆境誘導性及組織專一性表現，並可能參與調節種子發芽和植株株高。

關鍵字

Jumonji C基因 ； 組蛋白去甲基化酶 ； 水稻 ； 表觀遺傳修飾 ； 逆境反應 ； CRISPR/Cas9

並列摘要

The Jumonji C domain-containing ( JmjC ) histone demethylases regulate gene expression by modifying the methylation status on the N-terminal tails of histones, thereby changing the chromatin condensation. The importance of JmjC genes in plant has been studies mainly in Arabidopsis. To explore the role of the JmjC genes in rice, five JmjC genes ( OsJMJ715, OsJMJ716, OsJMJ718, OsJMJ719, and OsJMJ720 ) classified in the KDM3 group were functionally studied. Analysis of the response of JmjC genes to different abiotic stresses showed that dehydration and salinity significantly induced the expression of OsJMJ715, OsJMJ716, and OsJMJ718 both in roots and shoots. Heat stress ( 40°C ) significantly induced the expression of these five genes both in roots and shoots. Cold stress ( 4°C ) markedly induced the expression of these five JmjC genes in roots; in contrast, the expression of five JmjC genes was significantly suppressed by cold in shoots. Physiological roles of five JmjC genes were elucidated by analyzing T-DNA insertion mutants ( jmj716, jmj718, and jmj719 ) and CRISPR/Cas9-mediated mutants ( jmj715 and jmj720 ). A mutation in jmj716 showed a lethal phenotype after germination, while the jmj718 mutant caused a reduction in plant height. No apparent changes in phenotypes were observed in jmj715, jmj719 and jmj720 mutants. Taken together, the KDM3 group JmjC genes are differentially responsive to various abiotic stresses, and OsJMJ716 and OsJMJ718 may play pivotal roles in modulating genes crucial for seed germination and stem elongation of rice.

並列關鍵字

Jumonji C gene ； Histone demethylase ； Oryza sativa ； Epigenetic modifications ； Stress response ； CRISPR/Cas9

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