Role of a chalcone isomerase-like protein in flavonoid biosynthesis in Arabidopsis thaliana.
Role of a chalcone isomerase-like protein in flavonoid biosynthesis in Arabidopsis thaliana.
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查耳酮异构酶样蛋白在拟南芥类黄酮生物合成中的作用
DOI：
10.1093/jxb/erv413
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发表时间：
2015-12
影响因子：
6.9
通讯作者：
Pang Y
中科院分区：
文献类型：
--
作者：
Jiang W;Yin Q;Wu R;Zheng G;Liu J;Dixon RA;Pang Y
CHIL对拟南芥种子中原花青素和黄酮醇的积累至关重要，并且在类黄酮途径中具有独特的增强作用。黄酮类化合物是植物防御和人体健康的重要天然产物。虽然几乎所有的类黄酮途径基因已经通过生化和/或遗传学方法得到了很好的证明，但拟南芥查尔酮异构酶样（CHIL）基因的作用尚不清楚。两种种子颜色与野生型拟南芥相似的儿童突变体已经在这里被鉴定出来，但与其他已知的类黄酮途径基因相关的透明睾丸种子表型形成鲜明对比。CHIL功能缺失突变导致种子中原花青素和黄酮醇含量显著降低，但叶片中花青素含量不显著降低。过表达CHIL可以部分恢复CHIL突变体的突变表型，增加野生型拟南芥原花青素和黄酮醇的积累。然而，CHIL基因并不能挽救拟南芥中编码查尔酮异构酶的TT5的突变表型。对chil、tt5、chs和f3h突变体的平行表型和代谢分析显示，在遗传上，chil的功能与tt5相同。此外，研究表明，CHIL在拟南芥中与TT5共表达、共定位并相互作用，以产生类黄酮。综上所述，CHIL与TT5共同促进黄酮类化合物的产生，是黄酮类化合物途径中独特的增强剂。
CHIL is essential for the accumulation of proanthocyanidins and flavonols in seeds of Arabidopsis and it functions as a unique enhancer in the flavonoid pathway. Flavonoids are important natural products for plant defence and human health. Although almost all the flavonoid pathway genes have been well-documented by biochemical and/or genetic approaches, the role of the Arabidopsis chalcone isomerase-like (CHIL) gene remains unclear. Two chil mutants with a seed colour similar to that of wild-type Arabidopsis have been identified here, but in sharp contrast to the characteristic transparent testa seed phenotype associated with other known flavonoid pathway genes. CHIL loss-of-function mutations led to a strong reduction in the proanthocyanidin and flavonol levels in seeds, but not in the anthocyanin levels in leaves. CHIL over-expression could partially recover the mutant phenotype of the chil mutant and increased both proanthocyanidin and flavonol accumulation in wild-type Arabidopsis. However, the CHIL gene could not rescue the mutant phenotype of TT5 that encodes the intrinsic chalcone isomerase in Arabidopsis. Parallel phenotypical and metabolic analyses of the chil, tt5, chs, and f3h mutants revealed that, genetically, CHIL functions at the same step as TT5. Moreover, it is demonstrated that CHIL co-expresses, co-localizes, and interacts with TT5 in Arabidopsis for flavonoid production. Based on these genetic and metabolic studies, it is concluded that CHIL functions with TT5 to promote flavonoid production, which is a unique enhancer in the flavonoid pathway.