The poplar basic helix-loop-helix transcription factor BEE3 – Like gene affects biomass production by enhancing proliferation of xylem cells in poplar

• Published in: Biochemical and biophysical research communications Vol. 462; no. 1; pp. 64 - 70
• Main Authors: Noh, Seol Ah, Choi, Young-Im, Cho, Jin-Seong, Lee, Hyoshin
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 19.06.2015
• Subjects: 60 APPLIED LIFE SCIENCES; Amino Acid Sequence; AUGMENTATION; Basic Helix-Loop-Helix Transcription Factors - classification; Basic Helix-Loop-Helix Transcription Factors - genetics; Basic Helix-Loop-Helix Transcription Factors - metabolism; bHLH; BIOMASS; Brassinosteriod; Cell Proliferation - genetics; ELONGATION; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; GENES; HYBRIDIZATION; Hybridization, Genetic; MERISTEMS; Microscopy, Confocal; Molecular Sequence Data; PagBEE3L; Phylogeny; PLANT GROWTH; Plant Proteins - genetics; Plant Proteins - metabolism; PLANT STEMS; Plant Stems - genetics; Plant Stems - growth & development; Plant Stems - metabolism; Plants, Genetically Modified; Poplar; POPLARS; Populus; Populus - genetics; Populus - growth & development; Populus - metabolism; Populus alba; Reverse Transcriptase Polymerase Chain Reaction; Sequence Homology, Amino Acid; TRANSCRIPTION; TRANSCRIPTION FACTORS; TRANSGENIC PLANTS; Xylem; Xylem - cytology; Xylem - genetics; Xylem - metabolism; Poplar; Xylem; Biomass; PagBEE3L; Brassinosteriod; bHLH
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2015.04.109

Brassinosteroids (BRs) play important roles in many aspects of plant growth and development, including regulation of vascular cambium activities and cell elongation. BR-induced BEE3 (brassinosteroid enhanced expression 3) is required for a proper BR response. Here, we identified a poplar (Populus alba × Populus glandulosa) BEE3-like gene, PagBEE3L, encoding a putative basic helix-loop-helix (bHLH)-type transcription factor. Expression of PagBEE3L was induced by brassinolide (BL). Transcripts of PagBEE3L were mainly detected in stems, with the internode having a low level of transcription and the node having a relatively higher level. The function of the PagBEE3L gene was investigated through phenotypic analyses with PagBEE3L-overexpressing (ox) transgenic lines. This work particularly focused on a potential role of PagBEE3L in stem growth and development of polar. The PagBEE3L-ox poplar showed thicker and longer stems than wild-type plants. The xylem cells from the stems of PagBEE3L-ox plants revealed remarkably enhanced proliferation, resulting in an earlier thickening growth than wild-type plants. Therefore, this work suggests that xylem development of poplar is accelerated in PagBEE3L-ox plants and PagBEE3L plays a role in stem growth by increasing the proliferation of xylem cells to promote the initial thickening growth of poplar stems. •We identify the BEE3-like gene form hybrid poplar (Populus alba × Populus glandulosa).•We examine effects of overexpression of PagBEE3L on growth in poplar.•We found that 35S:BEE3L transgenic plants showed more rapid growth than wild-type plants.•BEE3L protein plays an important role in the development of plant stem.