Molecular features of secondary vascular tissue regeneration after bark girdling in Populus

• Published in: The New phytologist 2011-12, Vol.192 (4), p.869-884
• Main Authors: Zhang, Jing, Gao, Ge, Chen, Jia‐Jia, Taylor, Gail, Cui, Ke‐Ming, He, Xin‐Qiang
• Format: Article
• Language: English
• Subjects: Auxins; Bark; bark girdling; Cambium; Cambium - genetics; Cell cycle; Cell Cycle - genetics; Cell differentiation; Cells; Down-Regulation - genetics; Epigenesis, Genetic; Epigenetics; Gene Expression Profiling; Gene Expression Regulation, Plant; Genes; Genes, Plant - genetics; Girdling; microarray technology; Models, Biological; Pattern formation; Phloem; Phloem - genetics; Plant Bark - growth & development; Plant Bark - physiology; Plant Growth Regulators - metabolism; Plant growth substances; Plant hormones; Plant tissues; Plant Vascular Bundle - growth & development; Plant Vascular Bundle - physiology; Plants; Populus; Populus - anatomy & histology; Populus - genetics; Populus - growth & development; Populus - physiology; Populus tomentosa; Regeneration; Regeneration (biological); Regeneration - genetics; Regeneration - physiology; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; secondary vascular tissue; Stem cells; Tissue; Tissue engineering; tissue repair; Transcription Factors - genetics; Transcription Factors - metabolism; Transcriptome - genetics; transcriptome profiling; Trees; Up-Regulation - genetics; Vascular tissue; Vascular tissues; Xylem; Xylem - cytology; Xylem - genetics
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2011.03855.x

• Regeneration is a common strategy for plants to repair damage to their tissue after attacks from other organisms or physical assaults. However, how differentiating cells acquire regenerative competence and rebuild the pattern of new tissues remains largely unknown. • Using anatomical observation and microarray analysis, we investigated the morphological process and molecular features of secondary vascular tissue regeneration after bark girdling in trees. • After bark girdling, new phloem and cambium regenerate from differentiating xylem cells and rebuild secondary vascular tissue pattern within 1 month. Differentiating xylem cells acquire regenerative competence through epigenetic regulation and cell cycle re‐entry. The xylem developmental program was blocked, whereas the phloem or cambium program was activated, resulting in the secondary vascular tissue pattern re‐establishment. Phytohormones play important roles in vascular tissue regeneration. • We propose a model describing the molecular features of secondary vascular tissue regeneration after bark girdling in trees. It provides information for understanding mechanisms of tissue regeneration and pattern formation of the secondary vascular tissues in plants.