Premium
The proanthocyanidin‐specific transcription factor Md MYBPA 1 initiates anthocyanin synthesis under low‐temperature conditions in red‐fleshed apples
Author(s) -
Wang Nan,
Qu Changzhi,
Jiang Shenghui,
Chen Zijing,
Xu Haifeng,
Fang Hongcheng,
Su Mengyu,
Zhang Jing,
Wang Yicheng,
Liu Wenjun,
Zhang Zongying,
Lu Ninglin,
Chen Xuesen
Publication year - 2018
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14013
Subject(s) - anthocyanin , myb , malus , proanthocyanidin , flavonoid , transcription factor , flavonoid biosynthesis , biology , biochemistry , chemistry , botany , polyphenol , gene expression , gene , transcriptome , antioxidant
Summary In plants, flavonoids play critical roles in resistance to biotic and abiotic stresses, and contribute substantially to the quality, flavor, and nutritional quality of many fruit crops. In apple ( Malus × domestica ), inbreeding has resulted in severe decreases in the genetic diversity and flavonoid content. Over the last decade, we have focused on the genetic improvement of apple using wild red‐fleshed apple resources ( Malus sieversii f . niedzwetzkyana ). Here, we found that the MYB transcription factors ( TF s) involved in the synthesis of proanthocyanidins can be classified into TT 2 and PA 1 types. We characterized a PA 1‐type MYB transcription factor, Md MYBPA 1 , from red‐fleshed apple and identified its role in flavonoid biosynthesis using overexpression and knockdown‐expression transgenes in apple calli. We explored the relationship between TT 2‐ and PA 1‐type MYB TF s, and found that Md MYB 9/11/12 bind the Md MYBPA 1 promoter. In addition, Md MYBPA 1 responded to low temperature by redirecting the flavonoid biosynthetic pathway from proanthocyanidin to anthocyanin production. In binding analyses, Mdb HLH 33 directly bound to the low‐temperature‐responsive ( LTR ) cis ‐element of the Md MYBPA 1 promoter and promotes its activity. In addition, the calli expressing both Md MYBPA 1 and Mdb HLH 33 , which together form a complex, produced more anthocyanin under low temperature. Our findings shed light on the essential roles of PA 1‐type TF s in the metabolic network of proanthocyanidin and anthocyanin synthesis in plants. Studies on red‐fleshed wild apple are beneficial for breeding new apple varieties with high flavonoid contents.