Abstract
Background and Aims: Previous laboratory studies have suggested selection for root hair traits in future crop breeding to improve resource use efficiency and stress tolerance. However, data on the interplay between root hairs and open-field systems, under contrasting soils and climate conditions, are limited. As such, this study aims to experimentally elucidate some of the impacts that root hairs have on plant performance on a field scale.
Methods: A field experiment was set up in Scotland for two consecutive years, under contrasting climate conditions and different soil textures (i.e. clay loam vs. sandy loam). Five barley (Hordeum vulgare) genotypes exhibiting variation in root hair length and density were used in the study. Root hair length, density and rhizosheath weight were measured at several growth stages, as well as shoot biomass, plant water status, shoot phosphorus (P) accumulation and grain yield.
Key Results: Measurements of root hair density, length and its correlation with
rhizosheath weight highlighted trait robustness in the field under variable
environmental conditions, although significant variations were found between soil textures as the growing season progressed. Root hairs did not confer a notable advantage to barley under optimal conditions, but under soil water deficit root hairs enhanced plant water status and stress tolerance resulting in less negative leaf water potential and lower leaf abscisic acid concentration, while promoting shoot P accumulation. Furthermore, the presence of root hairs did not decrease yield under optimal conditions, while root hairs enhanced yield stability under drought.
Conclusions: Selecting for beneficial root hair traits can enhance yield stability
without diminishing yield potential, overcoming the breeder’s dilemma of trying to simultaneously enhance both productivity and resilience. Therefore, the maintenance or enhancement of root hairs can represent a key trait for breeding the next generation of crops for improved drought tolerance in relation to climate change.
Methods: A field experiment was set up in Scotland for two consecutive years, under contrasting climate conditions and different soil textures (i.e. clay loam vs. sandy loam). Five barley (Hordeum vulgare) genotypes exhibiting variation in root hair length and density were used in the study. Root hair length, density and rhizosheath weight were measured at several growth stages, as well as shoot biomass, plant water status, shoot phosphorus (P) accumulation and grain yield.
Key Results: Measurements of root hair density, length and its correlation with
rhizosheath weight highlighted trait robustness in the field under variable
environmental conditions, although significant variations were found between soil textures as the growing season progressed. Root hairs did not confer a notable advantage to barley under optimal conditions, but under soil water deficit root hairs enhanced plant water status and stress tolerance resulting in less negative leaf water potential and lower leaf abscisic acid concentration, while promoting shoot P accumulation. Furthermore, the presence of root hairs did not decrease yield under optimal conditions, while root hairs enhanced yield stability under drought.
Conclusions: Selecting for beneficial root hair traits can enhance yield stability
without diminishing yield potential, overcoming the breeder’s dilemma of trying to simultaneously enhance both productivity and resilience. Therefore, the maintenance or enhancement of root hairs can represent a key trait for breeding the next generation of crops for improved drought tolerance in relation to climate change.
| Original language | English |
|---|---|
| Pages (from-to) | 1-16 |
| Number of pages | 16 |
| Journal | Annals of Botany |
| Volume | 128 |
| Issue number | 1 |
| Early online date | 10 Oct 2020 |
| DOIs | |
| Publication status | Published - Jun 2021 |
Bibliographical note
ACKNOWLEDGEMENTS:We thank Mr Richard Keith, Mr Christopher Warden and the field staff of The James Hutton Institute for setting up, managing and maintaining the field trials.
FUNDING:
Aberdeen University and James Hutton staff were funded by BBSRC BB/J00868/1 and Dundee University staff by BBSRC BB/L025825/1. Contributions by Southampton university were funded by BBSRC SARISA BB/L025620/1. The James Hutton Institute receives financial support from the Rural & Environment Science & Analytical Services Division of the Scottish Government and TR is also funded by EPSRC EP/M020355/1, ERC 646809DIMR, BBSRC SARIC BB/P004180/1 and NERC NE/L00237/1. ICD is grateful for the support of a Newton Advanced Fellowship (NA160430).
Keywords
- agricultural sustainability
- barley
- drought tolerance
- grain yield
- Hordeum vulgare
- plant water status
- phosphorus
- rhizosheath
- root hairs
- root traits
- soil texture
Access to Document
- Marin_et_al_AoB_SignificanceOfRootsHairs_AAM
This is a pre-copyedited, author-produced version of an article accepted for publication in Annals of Botany following peer review. The version of record [insert complete citation information here] is available online at: xxxxxxx [insert URL and DOI of the article on the OUP website].