GHCU, a Molecular Chaperone, Regulates Leaf Curling by Modulating the Distribution of KNGH1 in Cotton

Authors

Yihao Zang
Chenyu Xu
Lishan Yu
Longen Ma
Lisha Xuan
Sunyi Yan
Yayao Zhang
Yiwen Cao
Xiaoran Li
Zhanfeng Si
Jieqiong Deng
Tianzhen Zhang
Yan Hu

Publication Date

7-1-2024

Journal

Advanced Science

Abstract

Leaf shape is considered to be one of the most significant agronomic traits in crop breeding. However, the molecular basis underlying leaf morphogenesis in cotton is still largely unknown. In this study, through genetic mapping and molecular investigation using a natural cotton mutant cu with leaves curling upward, the causal gene GHCU is successfully identified as the key regulator of leaf flattening. Knockout of GHCU or its homolog in cotton and tobacco using CRISPR results in abnormal leaf shape. It is further discovered that GHCU facilitates the transport of the HD protein KNOTTED1-like (KNGH1) from the adaxial to the abaxial domain. Loss of GHCU function restricts KNGH1 to the adaxial epidermal region, leading to lower auxin response levels in the adaxial boundary compared to the abaxial. This spatial asymmetry in auxin distribution produces the upward-curled leaf phenotype of the cu mutant. By analysis of single-cell RNA sequencing and spatiotemporal transcriptomic data, auxin biosynthesis genes are confirmed to be expressed asymmetrically in the adaxial-abaxial epidermal cells. Overall, these findings suggest that GHCU plays a crucial role in the regulation of leaf flattening through facilitating cell-to-cell trafficking of KNGH1 and hence influencing the auxin response level.

Keywords

Gossypium, Plant Leaves, Plant Proteins, Molecular Chaperones, Phenotype, Gene Expression Regulation, Plant, Indoleacetic Acids, auxin, cup‐shaped leaf, Gossypium hirsutum, map‐based cloning

Comments

Supplementary Materials

PMID: 38666376