Page 39 - 《华中农业大学学报（自然科学版）》2023年第1期

第 1 期 张焱 等：甜樱桃扩展蛋白 PavEXPA2 基因克隆与表达分析 33

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Cloning and expression of expansin PavEXPA2 gene in sweet cherries

ZHANG Yan,QIU Zhilang,SHEN Luonan,WEN Xiaopeng
The Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous

Region（Ministry of Education）/Institute of Agro-Bioengineering/College of Life Sciences，
Guizhou University， Guiyang 550025， China

Abstract Expansin is a kind of protein widely found in plants.It may relax the cell wall and plays an
important role in the growth and development，and the stress response of plants.The PavEXPA2 gene was
cloned and bioinformatically analyzed to uncover the structure and function of expansingene（EXPA） in
sweet cherries. The gene expression in different tissues including stems，flower buds，blooming flowers，

young leaves，old leaves，petioles of young leaves，petioles of old leaves，normal fruit stalks at the 2 abscis‐
sion peaks and about to abscission，the normal fruits at 2 abscission peaks and shedding，and under the abiot‐
ic stresses including using 20% PEG6000 and 20 mmol/L NaCl solutions to simulate drought and salt
stress for 0，2，4，6，and 8 h was profiled.The results showed that the full length of PavEXPA2 was 1 035
bp with the open reading frame （ORF） of 852 bp，encoding 283 amino acids.The putative protein has an
isoelectric point of 8.90 and a molecular mass of 30.81 ku，containing two transmembrane helical structures
and a signal peptide.The results of subcellular location showed that the protein of gene was located in the
cell wall.The results of tissue expression analysis showed that the expression level of PavEXPA2 was high‐
er in the easily abscised tissues of sweet cherry including flowers，stalks，fruits and petioles，with the highest
level in petioles about to abscission.Compared with the samples untreated，the expression of PavEXPA2 in
the drought-treated samples increased，and the expression reached the highest at 6 h，and then decreased.
Under the salt stress，the expression level of PavEXPA2 decreased first，then increased and then decreased，
and the expression level reached the highest at 6 h.Therefore，sweet cherries may resist stress by promoting
abscission through the up-regulation of PavEXPA2 gene.It will lay a theoretical foundation for further un‐
derstanding the role of PavEXPA2 in the growth and development of sweet cherries.
Keywords sweet cherry； pavEXPA2； gene cloning； bioinformatics； abiotic stress； organ abscission

（责任编辑：张志钰）