Overexpression of the PtrMYB002 gene Inhibits Growth of Arabidopsis thaliana and Enhances Its Drought Resistance

doi:10.7525/j.issn.1673-5102.2026.01.006

Abstract

Abstract:

This study addressed the issue of growth suppression and mortality in poplar caused by increasing global drought， focusing on the R2R3-MYB transcription factor PtrMYB002 from Populus trichocarpa. Utilizing methods including gene cloning， expression vector construction， genetic transformation of Arabidopsis thaliana， and transient transformation in poplar， combined with bioinformatics analysis， subcellular localization， phenotypic observation， physiological index measurement， and gene expression analysis， we investigated its role in regulating plant growth and drought tolerance. The results showed that PtrMYB002 was localized in the nucleus and its expression was significantly induced by drought and ABA treatment. Overexpression of PtrMYB002 gene significantly inhibited the cotyledon area， hypocotyl length， root length， rosette diameter， above-ground fresh mass， and inflorescenced stem height in Arabidopsis， but enhanced its drought tolerance. Under drought conditions， the transgenic lines exhibited significantly higher net CO? assimilation rate， electron transport rate（ETR）， actual photochemical efficiency（Y（Ⅱ））， photochemical quenching coefficient（qP）， and non-photochemical quenching coefficient（NPQ）， while the stomatal conductance， transpiration rate， and relative electrical conductivity were significantly lower compared to the wild-type（WT）. Concurrently， the expression levels of drought-responsive genes AtRD29A and AtDREB2 were significantly upregulated in the transgenic lines. Furthermore， in the ‘84K’ poplar with transient overexpression of PtrMYB002 gene， the expression levels of PagRD29A and PagDREB2B genes were significantly higher than that in the control group， indicating that this regulatory mechanism was likely conserved in poplar. In conclusion， the overexpression of PtrMYB002 gene suppressed growth in Arabidopsis while enhancing its drought tolerance， demonstrating a potential role of the gene in participation of “growth and defense trade-off” strategy， and provided new genetic resources and a theoretical basis for molecular breeding of drought-tolerant poplar.

Key words: Populus trichocarpa, Arabidopsis thaliana, PtrMYB002, growth and development, drought resistance

CLC Number:

Q344

Zheng LI, Fengxin CHEN, Yuqi LIU, Mingming LI, Jiacan YIN, Chao LIU, Xinli XIA. Overexpression of the PtrMYB002 gene Inhibits Growth of Arabidopsis thaliana and Enhances Its Drought Resistance[J]. Bulletin of Botanical Research, 2026, 46(1): 67-82.

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引物名称 Primer name	上游引物序列（5′→3′） Forward primer sequence（5′→3′）	引物名称 Primer name	下游引物序列（5′→3′） Reverse primer sequence（5′→3′）
AtRD29A-F	CGGGATTTGACGGAGAACCA	AtRD29A-R	GGTCTCTTCCCAGCTCAGTC
AtDREB2-F	CGAGCAGCCGAAGAAAAGGA	AtDREB2-R	GCAGGAACTTTGCGTTTCGG
PagRD29A-F	GCCACAAATGTCATGGCCTC	PagRD29A-R	TCGCAGCATTTTGTCCTTGTC
PagDREB2B-F	GTTCTGCGCTTGGGTTTAGC	PagDREB2B-R	CTTTCTTCGACCCCTTGCCT
PtrMYB002-F	CGTTAGCAACCTCCATGAAAGC	PtrMYB002-R	TCACCACTGTTAAGGACTCCAAC
AtActin2-F	AGTGGTCGTACAACCGGTATTGT	AtActin2-R	GATGGCATGAGGAAGAGAGAAAC
PagUBQ-F	AGACCTACACCAAGCCCAAGAAGAT	PagUBQ-R	CCAGCACCGCACTCAGCATTAG