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Function identification of MdTIR1 in apple root growth benefited from the predicted MdPPI network
Author(s) -
Liu Lin,
Yu Zipeng,
Xu Yang,
Guo Cheng,
Zhang Lei,
Wu Changai,
Yang Guodong,
Huang Jinguang,
Yan Kang,
Shu Huairui,
Zheng Chengchao,
Zhang Shizhong
Publication year - 2021
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/jipb.12996
Subject(s) - subnetwork , auxin , biology , malus , transgene , function (biology) , microbiology and biotechnology , gene , biochemistry , botany , computer security , computer science
Protein–protein interaction (PPI) network analysis is an effective method to identify key proteins during plant development, especially in species for which basic molecular research is lacking, such as apple ( Malus domestica ). Here, an MdPPI network containing 30 806 PPIs was inferred in apple and its quality and reliability were rigorously verified. Subsequently, a root‐growth subnetwork was extracted to screen for critical proteins in root growth. Because hormone‐related proteins occupied the largest proportion of critical proteins, a hormone‐related sub‐subnetwork was further extracted from the root‐growth subnetwork. Among these proteins, auxin‐related M. domestica TRANSPORT INHIBITOR RESISTANT 1 (MdTIR1) served as the central, high‐degree node, implying that this protein exerts essential roles in root growth. Furthermore, transgenic apple roots overexpressing an MdTIR1 transgene displayed increased primary root elongation. Expression analysis showed that MdTIR1 significantly upregulated auxin‐responsive genes in apple roots, indicating that it mediates root growth in an auxin‐dependent manner. Further experimental validation revealed that MdTIR1 interacted with and accelerated the degradation of MdIAA28, MdIAA43, and MdIAA46. Thus, MdTIR1‐mediated degradation of MdIAAs is critical in auxin signal transduction and root growth regulation in apple. Moreover, our network analysis and high‐degree node screening provide a novel research technique for more generally characterizing molecular mechanisms.