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 - 2015/8/1
Y1 - 2015/8/1
N2 - Summary 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. Significance Statement During leaf development, leaf cells gradually exit from their proliferation phase and enter the expansion stage with a basipetally ordered pattern initiating at the leaf tip, whereas the molecular mechanism directing this pattern is unknown. We identified a basipetally expressed gene CCR1, previously known to be required for lignin biosynthesis, to mediate this leaf development pattern through strictly controlling levels of FeA, an intermediate of lignin biosynthesis having antioxidant activity.
AB - Summary 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. Significance Statement During leaf development, leaf cells gradually exit from their proliferation phase and enter the expansion stage with a basipetally ordered pattern initiating at the leaf tip, whereas the molecular mechanism directing this pattern is unknown. We identified a basipetally expressed gene CCR1, previously known to be required for lignin biosynthesis, to mediate this leaf development pattern through strictly controlling levels of FeA, an intermediate of lignin biosynthesis having antioxidant activity.
U2 - 10.1111/tpj.12902
DO - 10.1111/tpj.12902
M3 - Journal article
C2 - 26058952
SN - 0960-7412
VL - 83
SP - 375
EP - 387
JO - Plant Journal
JF - Plant Journal
IS - 3
ER -