Root hairs facilitate rice root penetration into compacted layers

Xiuzhen Kong; Suhang Yu; Yali Xiong; Xiaoyun Song; Lucia Nevescanin-Moreno; Xiaoqing Wei; Jinliang Rao; Hu Zhou; Malcolm J Bennett; Bipin K Pandey; Guoqiang Huang

doi:10.1016/j.cub.2024.03.064

Root hairs facilitate rice root penetration into compacted layers

Curr Biol. 2024 Apr 17:S0960-9822(24)00404-4. doi: 10.1016/j.cub.2024.03.064. Online ahead of print.

Authors

Affiliations

¹ Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, SJTU-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 200240 Shanghai, China; Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, 200240 Shanghai, China.
² Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, SJTU-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 200240 Shanghai, China.
³ Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nottingham LE12 5RD, UK.
⁴ Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture, College of Land Science and Technology, China Agricultural University, Beijing, China.
⁵ Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nottingham LE12 5RD, UK. Electronic address: bipin.pandey@nottingham.ac.uk.
⁶ Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, SJTU-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 200240 Shanghai, China. Electronic address: huang19880901@sjtu.edu.cn.

PMID: 38653244
DOI: 10.1016/j.cub.2024.03.064

Abstract

Compacted soil layers adversely affect rooting depth and access to deeper nutrient and water resources, thereby impacting climate resilience of crop production and global food security. Root hair plays well-known roles in facilitating water and nutrient acquisition. Here, we report that root hair also contributes to root penetration into compacted layers. We demonstrate that longer root hair, induced by elevated auxin response during a root compaction response, improves the ability of rice roots to penetrate harder layers. This compaction-induced auxin response in the root hair zone is dependent on the root apex-expressed auxin synthesis gene OsYUCCA8 (OsYUC8), which is induced by compaction stress. This auxin source for root hair elongation relies on the auxin influx carrier AUXIN RESISTANT 1 (OsAUX1), mobilizing this signal from the root apex to the root hair zone. Mutants disrupting OsYUC8 and OsAUX1 genes exhibit shorter root hairs and weaker penetration ability into harder layers compared with wild type (WT). Root-hair-specific mutants phenocopy these auxin-signaling mutants, as they also exhibit an attenuated root penetration ability. We conclude that compaction stress upregulates OsYUC8-mediated auxin biosynthesis in the root apex, which is subsequently mobilized to the root hair zone by OsAUX1, where auxin promotes root hair elongation, improving anchorage of root tips to their surrounding soil environment and aiding their penetration ability into harder layers.

Keywords: anchorage; auxin; compacted layer; root hair; root penetration.