文献类型：期刊文献

英文题名：The class II KNOX transcription factors KNAT3 and KNAT7 synergistically regulate monolignol biosynthesis in Arabidopsis

作者：Qin, Wenqi[1,2] Yin, Qi[1,2] Chen, Jiajun[1,2] Zhao, Xianhai[1,2] Yue, Fengxia[3] He, Junbo[1,2] Yang, Linjie[3] Liu, Lijun[4] Zeng, Qingyin[5] Lu, Fachuang[3] Mitsuda, Nobutaka[6] Ohme-Takagi, Masaru[7] Wu, Ai-Min[1,2]

第一作者：Qin, Wenqi

通信作者：Wu, AM[1];Wu, AM[2]

机构：[1]South China Agr Univ, State Key Lab Conservat & Utilizat Subtrop Agrobi, Guangzhou 510642, Peoples R China;[2]South China Agr Univ, Coll Forestry & Landscape Architecture, Guangdong Key Lab Innovat Dev & Utilizat Forest P, Guangzhou 510642, Peoples R China;[3]South China Univ Technol, State Key Lab Pulp & Paper Engn, Guangzhou 510640, Peoples R China;[4]Shandong Agr Univ, Coll Forestry, State Forestry & Grassland Adm Key Lab Silvicultu, Tai An 271018, Shandong, Peoples R China;[5]Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Beijing 100091, Peoples R China;[6]Natl Inst Adv Ind Sci & Technol, Bioprod Res Inst, Tsukuba, Ibaraki 3058566, Japan;[7]Saitama Univ, Green Biol Res Ctr, Saitama 3388570, Japan

年份：2020

卷号：71

期号：18

起止页码：5469-5483

外文期刊名：JOURNAL OF EXPERIMENTAL BOTANY

收录：;Scopus(收录号：2-s2.0-85096440286);WOS:【SCI-EXPANDED(收录号:WOS:000577073500016)】；

基金：We thank the Arabidopsis Biological Resource Center for seeds of the T-DNA insertion mutant. Financial support for this work was obtained the National Natural Science Foundation of China (Grant Numbers 31870653, 31670670, 31811530009).

语种：英文

外文关键词：Cell wall; KNAT3; KNAT7; monolignol; lignin; secondary cell wall; xylem

摘要：The function of the transcription factor KNOTTED ARABIDOPSIS THALIANA7 (KNAT7) is still unclear since it appears to be either a negative or a positive regulator for secondary cell wall deposition with its loss-of-function mutant displaying thicker interfascicular and xylary fiber cell walls but thinner vessel cell walls in inflorescence stems. To explore the exact function of KNAT7, class II KNOTTED1-LIKE HOMEOBOX (KNOX II) genes in Arabidopsis including KNAT3, KNAT4, and KNAT5 were studied together. By chimeric repressor technology, we found that both KNAT3 and KNAT7 repressors exhibited a similar dwarf phenotype. Both KNAT3 and KNAT7 genes were expressed in the inflorescence stems and the knat3 knat7 double mutant exhibited a dwarf phenotype similar to the repressor lines. A stem cross-section of knat3 knat7 displayed an enhanced irregular xylem phenotype as compared with the single mutants, and its cell wall thickness in xylem vessels and interfascicular fibers was significantly reduced. Analysis of cell wall chemical composition revealed that syringyl lignin was significantly decreased while guaiacyl lignin was increased in the knat3 knat7 double mutant. Coincidently, the knat3 knat7 transcriptome showed that most lignin pathway genes were activated, whereas the syringyl lignin-related gene Ferulate 5-Hydroxylase (F5H) was down-regulated. Protein interaction analysis revealed that KNAT3 and KNAT7 can form a heterodimer, and KNAT3, but not KNAT7, can interact with the key secondary cell wall formation transcription factors NST1/2, which suggests that the KNAT3NST1/2 heterodimer complex regulates F5H to promote syringyl lignin synthesis. These results indicate that KNAT3 and KNAT7 synergistically work together to promote secondary cell wall biosynthesis.