Whole Exome Sequencing-Based Identification of a Novel Gene Involved in Root Hair Development in Barley (Hordeum vulgare L.).

Katarzyna Gajek,Iwona Szarejko,Urszula Korotko,Marek Marzec,Agnieszka Janiak,Beata Chmielewska

doi:10.3390/ijms222413411

Katarzyna Gajek, Iwona Szarejko + Show 4 more

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https://doi.org/10.3390/ijms222413411

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Abstract

Root hairs play a crucial role in anchoring plants in soil, interaction with microorganisms and nutrient uptake from the rhizosphere. In contrast to Arabidopsis, there is a limited knowledge of root hair morphogenesis in monocots, including barley (Hordeum vulgare L.). We have isolated barley mutant rhp1.e with an abnormal root hair phenotype after chemical mutagenesis of spring cultivar ‘Sebastian’. The development of root hairs was initiated in the mutant but inhibited at the very early stage of tip growth. The length of root hairs reached only 3% of the length of parent cultivar. Using a whole exome sequencing (WES) approach, we identified G1674A mutation in the HORVU1Hr1G077230 gene, located on chromosome 1HL and encoding a cellulose synthase-like C1 protein (HvCSLC1) that might be involved in the xyloglucan (XyG) synthesis in root hairs. The identified mutation led to the retention of the second intron and premature termination of the HvCSLC1 protein. The mutation co-segregated with the abnormal root hair phenotype in the F2 progeny of rhp1.e mutant and its wild-type parent. Additionally, different substitutions in HORVU1Hr1G077230 were found in four other allelic mutants with the same root hair phenotype. Here, we discuss the putative role of HvCSLC1 protein in root hair tube elongation in barley.

Highlights

Root hairs (RHs) are long tubular outgrowths of root epidermal cells that play a role in absorbing water and nutrients from the soil
Expansins are involved in cell wall loosening that is required for root hair development [18,19,20], the abnormal root hair trait did not co-segregate with the C773T mutation detected in the hvexpb5.i allele (Supplementary Table S1)
We have found that HORVU1Hr1G077230 gene encodes a cellulose synthase-like C1 (HvCSLC1) encodes a protein with glucan synthase activity that probably is involved in XyG biosynthesis in barley root hairs

Summary

Introduction

Root hairs (RHs) are long tubular outgrowths of root epidermal (rhizodermal) cells that play a role in absorbing water and nutrients from the soil. They increase significantly root surface; for example, it was estimated in barley that the root surface can be expanded by 112–245%, depending on the root hair length of the cultivar [1]. Their role is especially important when plants grow under stressful conditions, such as phosphorus deficiency or drought [2,3]. There is a limited knowledge on molecular mechanisms controlling root hair morphogenesis in monocots, including barley

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Discussion

Conclusion