Recent advances in molecular regulatory mechanisms of DNA methylation in plant tissue culture

doi:10.12302/j.issn.1000-2006.202302020

JOURNAL OF NANJING FORESTRY UNIVERSITY ›› 2023, Vol. 47 ›› Issue (6): 1-8.doi: 10.12302/j.issn.1000-2006.202302020

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Recent advances in molecular regulatory mechanisms of DNA methylation in plant tissue culture

GUO Ying(), YANG Ganggui(), WU Yuhan, HE Jie, HE Yujie, LIAO Haoran, XUE Liangjiao()

State Key Laboratory of Tree Genetics and Breeding, Co-Innovation Center for Sustainable Forestry in Southern China, Jiangsu Key Laboratory for Poplar Germplasm Enhancement and Variety Improvement, College of Forestry and Grassland, Nanjing Forestry University, Nanjing 210037, China

Received:2023-02-18 Revised:2023-06-21 Online:2023-11-30 Published:2023-11-23

Abstract

Abstract:

Exerting remarkable cell totipotence, plants are able to regenerate tissues/organs and even individuals from differentiated cells activated by wound stress and/or hormonal cues. Based on the theory of plant cell totipotency, techniques of plant tissue culture have been widely used in rapid propagation, germplasm conservation, and plant breeding as a type of conserved epigenetic modification. However, the understanding of how plant cells retain both differentiated status and developmental plasticity is still obscure, especially at the epigenetic level. DNA methylation is an evolutionarily conserved epigenetic modification that can intricately coordinate cell fate transition and pluripotency establishment during the plant regenerate process. In the work, the recent progress in the regulation of plant regeneration through DNA methylation was summarized, starting from the formation of callus and somatic embryogenesis during tissue culture. Firstly, the change patterns of DNA methylation in different plant regeneration processes were analyzed, showing that both explants type and regeneration phase had an effect on DNA methylation levels. The role of some DNA methyltransferase in plant regeneration was studied, such as DNA Methyltransferase1 (MET1), whose deletion can lead to increased WUS expression and promote shoot regeneration. RNA-directed DNA methylation (RdDM) is the main molecular pathway responsible for de novo DNA methylation in all contexts and is believed to play an important role in plant regeneration. Meanwhile, we analyzed the molecular regulatory mechanisms of DNA methylation on the expression of regenerative genes, such as BBM (baby boom), WOX (wuschel-related homeobox), WIN (wound induced dedifferentiation), etc. Finally, we discussed the future research directions of DNA methylation in the field of plant regeneration. The combination of tissue culture and genetic engineering will provide opportunities for efficient reproduction and precise cultivation of agricultural and forestry crops. Further, the regeneration-related genes reported in this study will provide candidates for plant regeneration research of genetic and molecular mechanisms.

Key words: plant tissue culture, DNA methylation, callus, somatic embryogenesis

CLC Number:

Q943
S722

GUO Ying, YANG Ganggui, WU Yuhan, HE Jie, HE Yujie, LIAO Haoran, XUE Liangjiao. Recent advances in molecular regulatory mechanisms of DNA methylation in plant tissue culture[J]. JOURNAL OF NANJING FORESTRY UNIVERSITY, 2023, 47(6): 1-8.

Figures/Tables 2

Fig. 1

Table 1

Effects of DNA methylation on key genes of plant regeneration during plant tissue culture and development"

序号 No.	基因名称 gene symbol	功能 function	物种 species
1	ARR3 (arabidopsis response regulator 3)	参与细胞分裂素调节;5-azaC处理后基因表达上调,发生低甲基化促进桃叶片愈伤组织诱导	桃 Prunus persica^[45]
2	BBM (baby boom)	影响体细胞胚胎发生;表达量升高,甲基化水平降低促进胚胎发生(胚性愈伤组织中高表达)	凹唇姜 Boesenbergia rotunda^[14]
3	CRY1 (cryptochrome 1)	调节细胞分裂素信号,促进芽再生器官的新生	拟南芥 Arabidopsis thaliana^[46]
4	CCD1 (carotenoid cleavage dioxygenases 1)	降解类胡萝卜素;5-azaC处理导致全基因组去甲基化,类胡萝卜素含量降低	柑橘 Citrus paradisi^[47]
5	CMT2/CMT3 (chromomethylase 2/chromomethylase 3)	参与mCHG维持;5-azaC处理抑制了叶外植体愈伤组织的形成和不定芽再生	草莓 Fragaria vesca^[9]
6	CMT3 (chromomethylase 3)	维持DNA甲基化;5-azaC处理后基因表达显著下调,DNA甲基化降低促进桃叶片愈伤组织诱导	桃 P. persica^[45]
		维持DNA甲基化;表达量升高DNA甲基化水平降低,促进体细胞胚胎的发生和再生	凹唇姜 B. rotunda^[48]
7	DRM2 (domains rearranged methyltransferase)	维持CHH甲基化	毛果杨 Populus trichocarpa^[49]
		表达量升高DNA甲基化水平降低,促进体细胞胚胎的发生和再生	凹唇姜 B. rotunda^[48]
8		维持CG甲基化;低甲基化,met1-3突变体芽再生能力更高	拟南芥 A. thaliana^[46]
	MET1 (methyltransferase 1)	维持DNA甲基化;表达量升高DNA甲基化水平降低,促进体细胞胚胎的发生和再生	凹唇姜 B. rotunda^[48]
		维持DNA甲基化;幼苗和嫩叶中偏好表达	柑橘 C. paradisi^[47]
9	ROS1 (repressor of silencing 1)	DNA甲基化水平降低,促进球状胚形成	龙眼 Dimocarpus longan^[30]
10	SERK (somatic embryogenesis receptor-like kinase)	影响体细胞胚胎发生;表达量升高,甲基化水平降低促进胚胎发生(胚性愈伤组织中高表达)	凹唇姜 B. rotunda^[14]
11	WIN (wound-induced)	诱导细胞去分化和增殖;发生去甲基化,基因表达上调促进愈伤组织形成	草莓 F. nilgerrensis^[50]
12	WOX (wuschel-related homeobox)	参与顶端分生组织发生;发生去甲基化,基因表达上调促进愈伤组织形成	草莓 F. nilgerrensis^[50]
13	WUS (wuschel-related homeobox)	调控植物再生;低甲基化激活了生长素和WUS相关基因表达,提高植物再生能力	棉花 Gossypium hirsutum^[51]
		影响体细胞胚胎发生;表达量升高,甲基化水平降低促进胚胎发生(分生组织中表达最高,其次是胚性愈伤)	凹唇姜 B. rotunda^[14]

Table 1

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Recent advances in molecular regulatory mechanisms of DNA methylation in plant tissue culture

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