The Role of Transcription Factors in the Regulation of Plant Shoot Branching

Abstract

Transcription factors, also known as trans-acting factors, balance development and stress responses in plants. Branching plays an important role in plant morphogenesis and is closely related to plant biomass and crop yield. The apical meristem produced during plant embryonic development repeatedly produces the body of the plant, and the final aerial structure is regulated by the branching mode generated by axillary meristem (AM) activities. These branching patterns are regulated by two processes: AM formation and axillary bud growth. In recent years, transcription factors involved in regulating these processes have been identified. In addition, these transcription factors play an important role in various plant hormone pathways and photoresponses regulating plant branching. In this review, we start from the formation and growth of axillary meristems, including the regulation of hormones, light and other internal and external factors, and focus on the transcription factors involved in regulating plant branching and development to provide candidate genes for improving crop architecture through gene editing or directed breeding.

Comparative Transcriptome Analysis Reveals Inhibitory Roles of Strigolactone in Axillary Bud Outgrowth in Ratoon Rice

“…Transcription factors (TFs) play an extremely important role in receiving various phytohormone signals and co-regulating plant growth and development [ 38 , 39 , 40 ]. Axillary bud outgrowth is an important developmental process regulated by various transcription factors.…”

Over-expression of CcMYB24, encoding a R2R3-MYB transcription factor from a high-leaf-number mutant of Cymbidium, increases the number of leaves in Arabidopsis

“…According to the results of sequence similarity analysis, CcMYB24 appeared to be a RAX2-like gene which belongs to the R2R3-MYB transcription factor gene family. Many studies have proved that the RAX homolog genes play important roles in determination of axillary meristems by generating a tissue environment conducive to the establishment of meristems to control the spatial pattern of axillary meristems development (reviewed by Zhang et al, 2022 ), thus participate in branching and leaf development. In Arabidopsis , transcripts of RAX genes accumulated in the axils of young leaf primordia and controlled a very early step of axillary meristem initiation, with rax mutants showing new phenotypes characterized by defects in lateral bud formation in overlapping zones along the shoot axis ( Müller, Schmitz & Theres, 2006 ).…”

“…In Chrysanthemum morifolium , CmRAX2 was expressed in the lateral branches and roots, with overexpression of CmRAX2 leading to increases in lateral branch number and plant height ( Song et al, 2022 ). RAX genes were also be found to participate in shoot branching and leaf dissection in tomato ( Busch et al, 2011 ; Zhang et al, 2022 ). Based on these evidences, it could be inferred that the CcMYB24 may be responsible for the variation in foliage traits shown by ‘TRIR-2’.…”

Transcriptome analysis during axillary bud growth in chrysanthemum (chrysanthemum×morifolium)

“…Mutants of genes associated with meristem development have been analyzed in a range of plants including Pisum sativum , Petunia × atkinsiana , Oryza sativa L., Nicotiana tabacum L., and Arabidopsis thaliana , providing further evidence that shoot activation can be controlled by the auxin transporter-based system ( Booker, Chatfield & Leyser, 2003 ; Sorefan et al, 2003 ; Snowden et al, 2005 ; Arite et al, 2007 ; Leyser, 2009 ). Plant hormones regulate the growth and development of plants universally, and the most important of these hormones is auxin, which was one of the first plant hormones to be discovered ( Chatfield et al, 2000 ; Souza et al, 2003 ; Shi et al, 2019 ; Zhang et al, 2022 ). GAs belong to the diterpene family and are essential for the growth and development of plants.…”