Overexpression of Mulberry MnERF2 Enhances Resistance to Drought in Arabidopsis thaliana

doi:10.13560/j.cnki.biotech.bull.1985.2025-0448

Abstract

Abstract:

Objective AP2/ERF transcription factors are plant-specific regulators that play a critical role in plant responses to abiotic stresses, such as low temperature, drought, waterlogging, and high salinity. Elucidating the molecular function of the mulberry ERF transcription factor MnERF2 in drought stress response may provide a theoretical foundation and genetic resources for stress-resistant mulberry breeding. Method MnERF2-overexpressing Arabidopsis thaliana lines were obtained via the floral dip method. Both transgenic seedlings and mature plants were subjected to drought stress, followed by phenotypic observation and physiological/biochemical analysis. Result The water loss rate of MnERF2-overexpressing A. thaliana lines is significantly lower than that of the wild-type. The overexpressingseedlings presented superior root development and mature transgenic plants showed significant increase in biomass accumulation and chlorophyll content under drought stress. The overexpressing lines demonstrated enhanced activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione S-transferase (GST). Levels of ascorbic acid (ASA), glutathione (GSH), and proline significantly elevated, meanwhile the relative electrical conductivity, malondialdehyde (MDA) content, and the levels of reactive oxygen species (ROS; O₂^•-, H₂O₂, •OH) markedly reduced under drought stress. Conclusion MnERF2 positively regulates the responses to drought stress. Overexpressing MnERF2 increase the tolerance to drought in transgenic A. thaliana by improving water retention and biomass accumulation, promoting proline biosynthesis, boosting antioxidant enzyme activity, and increasing antioxidant content.

Key words: Arabidopsis thaliana, overexpression, mulberry, MnERF2, resistance to drought

DONG Ya-ru, NIE Yu-xia, ZHU Hong, WANG Zhao-hong, LIU Hui-fen, GUO Guang. Overexpression of Mulberry MnERF2 Enhances Resistance to Drought in Arabidopsis thaliana[J]. Biotechnology Bulletin, 2026, 42(4): 182-189.

Figures/Tables 8

Table 1 Primers used in this study

用途 Application	引物名称 Primer name	序列 Sequence （5′‒3′）
PCR验证 PCR verification	pROKⅡ-F	CTATCCTTCGCAAGACCCTTCCTC
PCR验证 PCR verification	pROKⅡ-R	GACGTTGTAAAACGACGGCCAGTG
实时荧光定量 PCR Quantitative real-time PCR	MnERF2-F	TCCCGTTGGAAGCCGGGA
	MnERF2-R	CGACAGAGGCGGGACGTT
	TUB2-F	GCCAATCCGGTGCTGGTAACA
	TUB2-R	CATACCAGATCCAGTTCCTCCTCCC
	AtACTIN-F	CCAGCCATCGCTCATCGGAATG
	AtACTIN-R	CAGACACTGTATTTTCTCTCTG

Fig. 1 Resistance screening(A), PCR verification(B), and expression analysis (C) of A. thaliana overexpressing MnERF2M: Marker 2 000. WT: Wild-type Arabidopsis thaliana. ‒: Negative control. L1‒L5: Transgenic lines. Different lowercase letters indicate significant differences (P<0.05). The same below

Fig. 2 Evaluation of drought resistance in A. thaliana seedlings overexpressing MnERF2A: The growth of transgenic A. thaliana and WT plants (Scale bar=1 cm). B: Primary root length of transgenic A. thaliana and WT plants. C: Water loss rate of transgenic A. thaliana and WT plants under normal growth conditions

Fig. 3 Growth characteristics of MnERF2-overexpressing A. thaliana seedlings under drought stressA: Phenotypes (Scale bar=1 cm). B: Fresh weight. C: Total chlorophyll content

Fig. 4 Analysis of relative electrolyte leakage and MDA content in MnERF2-overexpressing A. thaliana under drought stress

Fig. 5 Content analysis of O2•-, H2O2, •OH in MnERF2-overexpressing A. thaliana under drought stress

Fig. 6 Activity analysis of SOD, POD, CAT and GST in MnERF2-overexpressing A. thaliana under drought stress

Fig. 7 Content analysis of AsA, GSH and proline in MnERF2-overexpressing A. thaliana under drought stress

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