Functional Analysis of the PgCesA3 White Spruce Cellulose Synthase Gene Promoter in Secondary Xylem
Cellulose is an essential structural component of the plant cell wall. Its biosynthesis involves genes encoding cellulose synthase enzymes and a complex transcriptional regulatory network. Three cellulose synthases have been identified in conifers as being potentially involved in secondary cell wall...
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Published in | Frontiers in plant science Vol. 10; p. 626 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Switzerland
Frontiers Media S.A
28.05.2019
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Subjects | |
Online Access | Get full text |
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Summary: | Cellulose is an essential structural component of the plant cell wall. Its biosynthesis involves genes encoding cellulose synthase enzymes and a complex transcriptional regulatory network. Three cellulose synthases have been identified in conifers as being potentially involved in secondary cell wall biosynthesis because of their preferential expression in xylem tissues; however, no direct functional association has been made to date. In the present work, we characterized the white spruce [
(Moench) Voss] cellulose synthase
gene and 5' regulatory elements. Phylogenetic analysis showed that
genes grouped with secondary cell wall-associated Arabidopsis cellulose synthase genes, such as
, and
. We produced transgenic spruce expressing the GUS reporter gene driven by the
promoter. We observed blue staining in differentiating xylem cells from stem and roots, and in foliar guard cells indicating that
is clearly involved in secondary cell wall biosynthesis. The promoter region sequence of
contained several putative MYB cis-regulatory elements including AC-I like motifs and secondary wall MYB-responsive element (SMRE); however, it lacked SMRE4, 7 and 8 that correspond to the sequences of AC-I, II, and III. Based on these findings and results of previous transient trans-activation assays that identified interactions between the
promoter and different MYB transcription factors, we performed electrophoretic mobility shift assays with MYB recombinant proteins and cis-regulatory elements present in the
promoter. We found that PgMYB12 bound to a canonical AC-I element identified in the
PAL promoter and two AC-I like elements. We hypothesized that the PgMYB12 could regulate
in roots based on previous expression results. This functional study of
sequences and promoter opens the door for future studies on the interaction between PgMYBs and the
regulatory elements. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Reviewed by: Francisco M. Cánovas, University of Málaga, Spain; Misato Ohtani, Nara Institute of Science and Technology (NAIST), Japan This article was submitted to Plant Physiology, a section of the journal Frontiers in Plant Science Edited by: Elisabeth Jamet, Université Toulouse III Paul Sabatier, France |
ISSN: | 1664-462X 1664-462X |
DOI: | 10.3389/fpls.2019.00626 |