RRC ID 55795
Author Li X, Speicher TL, Dees DCT, Mansoori N, McManus JB, Tien M, Trindade LM, Wallace IS, Roberts AW.
Title Convergent evolution of hetero-oligomeric cellulose synthesis complexes in mosses and seed plants.
Journal Plant J
Abstract In seed plants, cellulose is synthesized by rosette-shaped cellulose synthesis complexes (CSCs) that are obligate hetero-oligomeric, comprising three non-interchangeable cellulose synthase (CESA) isoforms. The moss Physcomitrella patens has rosette CSCs and seven CESAs, but its common ancestor with seed plants had rosette CSCs and a single CESA gene. Therefore, if P. patens CSCs are hetero-oligomeric, then CSCs of this type evolved convergently in mosses and seed plants. Previous gene knockout and promoter swap experiments showed that PpCESAs from class A (PpCESA3 and PpCESA8) and class B (PpCESA6 and PpCESA7) have non-redundant functions in secondary cell wall cellulose deposition in leaf midribs, whereas the two members of each class are redundant. Based on these observations, we proposed the hypothesis that the secondary class A and class B PpCESAs associate to form hetero-oligomeric CSCs. Here we show that transcription of secondary class A PpCESAs is reduced when secondary class B PpCESAs are knocked out and vice versa, as expected for genes encoding isoforms that occupy distinct positions within the same CSC. The class A and class B isoforms co-accumulate in developing gametophores and co-immunoprecipitate, suggesting that they interact to form a complex in planta. Finally, secondary PpCESAs interact with each other, whereas three of four fail to self-interact when expressed in two different heterologous systems. These results are consistent with the hypothesis that obligate hetero-oligomeric CSCs evolved independently in mosses and seed plants and we propose the constructive neutral evolution hypothesis as a plausible explanation for convergent evolution of hetero-oligomeric CSCs.
Volume 99(5)
Pages 862-876
Published 2019-9-1
DOI 10.1111/tpj.14366
PMID 31021018
PMC PMC6711812
MeSH Bryopsida / enzymology Bryopsida / genetics* Bryopsida / metabolism* Cell Wall Cellulose / biosynthesis* Cellulose / chemistry* Gene Expression Regulation, Plant Gene Knockout Techniques Genes, Plant / genetics Glucosyltransferases / genetics Glucosyltransferases / metabolism Plant Leaves Plant Proteins / genetics Protein Isoforms Seeds / genetics* Seeds / metabolism*
IF 5.726
Times Cited 0
Arabidopsis / Cultured plant cells, genes pdp38142 pdp39044