文献类型： 外文期刊

作者： Nieuwenhuizen, Niels J. ¹ ; Chen, Xiuyin ¹ ; Pellan, Mickael ¹ ; Zhang, Lei ¹ ; Guo, Lindy ¹ ; Laing, William A. ⁴ ; S ¹ ;

作者机构： 1.New Zealand Inst Plant & Food Res Ltd PFR, Private Bag 92169, Auckland 1142, New Zealand

2.Univ Auckland, Sch Biol Sci, Private Bag 92019, Auckland 1142, New Zealand

3.Hubei Acad Agr Sci, Inst Fruit & Tea, Wuhan 430064, Peoples R China

4.PFR, Private Bag 11600, Palmerston North 4442, New Zealand

5.PFR, 55 Old Mill Rd,RD 3, Motueka 7198, New Zealand

关键词： Kiwifruit; Wounding; Ethylene; Biosynthesis; Regulation; NAC; Transcription factors

期刊名称：BMC PLANT BIOLOGY （ 影响因子：4.215； 五年影响因子：4.96 ）

ISSN： 1471-2229

年卷期： 2021 年 21 卷 1 期

页码：

收录情况： SCI

摘要： Background The phytohormone ethylene controls many processes in plant development and acts as a key signaling molecule in response to biotic and abiotic stresses: it is rapidly induced by flooding, wounding, drought, and pathogen attack as well as during abscission and fruit ripening. In kiwifruit (Actinidia spp.), fruit ripening is characterized by two distinct phases: an early phase of system-1 ethylene biosynthesis characterized by absence of autocatalytic ethylene, followed by a late burst of autocatalytic (system-2) ethylene accompanied by aroma production and further ripening. Progress has been made in understanding the transcriptional regulation of kiwifruit fruit ripening but the regulation of system-1 ethylene biosynthesis remains largely unknown. The aim of this work is to better understand the transcriptional regulation of both systems of ethylene biosynthesis in contrasting kiwifruit organs: fruit and leaves. Results A detailed molecular study in kiwifruit (A. chinensis) revealed that ethylene biosynthesis was regulated differently between leaf and fruit after mechanical wounding. In fruit, wound ethylene biosynthesis was accompanied by transcriptional increases in 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS), ACC oxidase (ACO) and members of the NAC class of transcription factors (TFs). However, in kiwifruit leaves, wound-specific transcriptional increases were largely absent, despite a more rapid induction of ethylene production compared to fruit, suggesting that post-transcriptional control mechanisms in kiwifruit leaves are more important. One ACS member, AcACS1, appears to fulfil a dominant double role; controlling both fruit wound (system-1) and autocatalytic ripening (system-2) ethylene biosynthesis. In kiwifruit, transcriptional regulation of both system-1 and -2 ethylene in fruit appears to be controlled by temporal up-regulation of four NAC (NAM, ATAF1/2, CUC2) TFs (AcNAC1-4) that induce AcACS1 expression by directly binding to the AcACS1 promoter as shown using gel-shift (EMSA) and by activation of the AcACS1 promoter in planta as shown by gene activation assays combined with promoter deletion analysis. Conclusions Our results indicate that in kiwifruit the NAC TFs AcNAC2-4 regulate both system-1 and -2 ethylene biosynthesis in fruit during wounding and ripening through control of AcACS1 expression levels but not in leaves where post-transcriptional/translational regulatory mechanisms may prevail.