TY - JOUR

T1 - CCR1, an enzyme required for lignin biosynthesis in Arabidopsis, mediates cell proliferation exit for leaf development

AU - Xue, Jingshi

AU - Luo, Dexian

AU - Xu, Deyang

AU - Zeng, Minhuan

AU - Cui, Xiaofeng

AU - Li, Laigeng

AU - Huang, Hai

N1 - © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

PY - 2015

Y1 - 2015

N2 - After initiation, leaves first undergo rapid cell proliferation. During subsequent development, leaf cells gradually exit the proliferation phase and enter the expansion stage, following a basipetally ordered pattern starting at the leaf tip. The molecular mechanism directing this pattern of leaf development is as yet poorly understood. By genetic screening and characterization of Arabidopsis mutants defective in exit from cell proliferation, we show that the product of the CINNAMOYL CoA REDUCTASE (CCR1) gene, which is required for lignin biosynthesis, participates in the process of cell proliferation exit in leaves. CCR1 is expressed basipetally in the leaf, and ccr1 mutants exhibited multiple abnormalities, including increased cell proliferation. The ccr1 phenotypes are not due to the reduced lignin content, but instead are due to the dramatically increased level of ferulic acid (FeA), an intermediate in lignin biosynthesis. FeA is known to have antioxidant activity, and the levels of reactive oxygen species (ROS) in ccr1 were markedly reduced. We also characterized another double mutant in CAFFEIC ACID O-METHYLTRANSFERASE (comt) and CAFFEOYL CoA 3-O-METHYLTRANSFERASE (ccoaomt), in which the FeA level was dramatically reduced. Cell proliferation in comt ccoaomt leaves was decreased, accompanied by elevated ROS levels, and the mutant phenotypes were partially rescued by treatment with FeA or another antioxidant (N-acetyl-L-cysteine). Taken together, our results suggest that CCR1, FeA and ROS coordinate cell proliferation exit in normal leaf development.

AB - After initiation, leaves first undergo rapid cell proliferation. During subsequent development, leaf cells gradually exit the proliferation phase and enter the expansion stage, following a basipetally ordered pattern starting at the leaf tip. The molecular mechanism directing this pattern of leaf development is as yet poorly understood. By genetic screening and characterization of Arabidopsis mutants defective in exit from cell proliferation, we show that the product of the CINNAMOYL CoA REDUCTASE (CCR1) gene, which is required for lignin biosynthesis, participates in the process of cell proliferation exit in leaves. CCR1 is expressed basipetally in the leaf, and ccr1 mutants exhibited multiple abnormalities, including increased cell proliferation. The ccr1 phenotypes are not due to the reduced lignin content, but instead are due to the dramatically increased level of ferulic acid (FeA), an intermediate in lignin biosynthesis. FeA is known to have antioxidant activity, and the levels of reactive oxygen species (ROS) in ccr1 were markedly reduced. We also characterized another double mutant in CAFFEIC ACID O-METHYLTRANSFERASE (comt) and CAFFEOYL CoA 3-O-METHYLTRANSFERASE (ccoaomt), in which the FeA level was dramatically reduced. Cell proliferation in comt ccoaomt leaves was decreased, accompanied by elevated ROS levels, and the mutant phenotypes were partially rescued by treatment with FeA or another antioxidant (N-acetyl-L-cysteine). Taken together, our results suggest that CCR1, FeA and ROS coordinate cell proliferation exit in normal leaf development.

U2 - 10.1111/tpj.12902

DO - 10.1111/tpj.12902

M3 - Journal article

C2 - 26058952

VL - 83

SP - 375

EP - 387

JO - Plant Journal

JF - Plant Journal

SN - 0960-7412

IS - 3

ER -