Open AccessTaMOR is essential for root initiation and improvement of root system architecture in wheat
Author(s) -
Li Chaonan,
Wang Jingyi,
Li Long,
Li Jialu,
Zhuang Mengjia,
Li Bo,
Li Qiaoru,
Huang Junfang,
Du Yan,
Wang Jinping,
Fan Zipei,
Mao Xinguo,
Jing Ruilian
Publication year - 2022
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.13765
Subject(s) - biology , root system , lateral root , crown (dentistry) , mutant , gene , auxin , botany , arabidopsis , genetics , medicine , dentistry
Summary Optimal root system architecture is beneficial for water‐fertilizer use efficiency, stress tolerance and yield improvement of crops. However, because of the complexity of root traits and difficulty in phenotyping deep roots, the study on mechanisms of root development is rarely reported in wheat ( Triticum aestivum L.). In this study, we identified that the LBD (LATERAL ORGAN BOUNDARIES DOMAIN) gene TaMOR ( MORE ROOT in wheat) determines wheat crown root initiation. The mor mutants exhibited less or even no crown root, dwarfism, less grain number and lodging caused by few roots. The observation of cross sections showed that crown root initiation is inhibited in the mor mutants. Molecular assays revealed that TaMOR interacts with the auxin response factor ARF5 to directly induce the expression of the auxin transporter gene PIN2 ( PIN‐FORMED 2 ) in the root base to regulate crown root initiation. In addition, a 159‐bp MITE (miniature inverted‐repeat transposable element) insertion causing DNA methylation and lower expression of TaMOR‐B was identified in TaMOR‐B promoter, which is associated with lower root dry weight and shorter plant height. The results bring new light into regulation mechanisms of crown root initiation and offer a new target for the improvement of root system architecture in wheat.