Ag Data Commons
Browse

File(s) stored somewhere else

Please note: Linked content is NOT stored on Ag Data Commons and we can't guarantee its availability, quality, security or accept any liability.

The Populus Homeobox Gene ARBORKNOX2 Regulates Secondary Growth in trees

dataset
posted on 2024-01-27, 04:50 authored by Institute of Forest Genetics, USDA FOREST SERVICE
Currently little is known about the genetic mechanisms regulating the vascular cambium or the secondary growth of stems. We show here that the Populus Class I KNOX homeobox gene ARBORKNOX2 (ARK2) regulates both cell division in the cambium region and the differentiation of daughter cells in secondary xylem and phloem. ARK2 is expressed in the shoot apical meristem, and the vascular cambium region, reflecting some overlap in the regulation of these meristems. ARK2 is expressed broadly in the cambium region and in differentiating lignified cells types before becoming progressively restricted to the cambium. Populus overexpressing ARK2 present stem phenotypes with precocious cambium formation, delayed differentiation of cambium daughter cells, a wider cambium region, and ultimately less phloem fibers and secondary xylem. In contrast, Populus expressing RNAi or amicroRNA that target ARK2 transcripts present precocious differentiation of secondary phloem fibers and xylem, and ultimately more secondary xylem tissue and thicker secondary cell walls in phloem fibers and secondary xylem cells. These phenotypes in turn correlate with changes in the expression of genes affecting cell division, auxin, and cell wall synthesis and lignification that indicate that ARK2 primarily affects woody tissue development by regulation of cell differentiation. Notably, wood properties associated with secondary cell wall synthesis are negatively associated with ARK2 expression, including lignin and cellulose content. Together, our results suggest that ARK2 functions primarily by negatively regulating cell differentiation during secondary growth. We propose that ARK2 may identify a co-evolved regulatory module that influences complex wood properties relevant to ecological, industrial, and biofuels applications. Overall design: Gene expressions of three ARK2 overexpression transgenics plants and three ark2 artificial microRNA transgenics are detected with microarray. Gene expressions of four wild type plants sample are used as control.

History

Data contact name

BioProject Curation Staff

Publisher

National Center for Biotechnology Information

Temporal Extent Start Date

2009-09-30

Theme

  • Non-geospatial

ISO Topic Category

  • biota

National Agricultural Library Thesaurus terms

transcriptome; gene expression

Pending citation

  • No

Public Access Level

  • Public

Accession Number

PRJNA115607

Usage metrics

    Categories

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC