MicroRNA156 improves drought stress tolerance in alfalfa (Medicago sativa) by silencing SPL13

Muhammad Arshad; Biruk A Feyissa; Lisa Amyot; Banyar Aung; Abdelali Hannoufa

doi:10.1016/j.plantsci.2017.01.018

MicroRNA156 improves drought stress tolerance in alfalfa (Medicago sativa) by silencing SPL13

Plant Sci. 2017 May:258:122-136. doi: 10.1016/j.plantsci.2017.01.018. Epub 2017 Feb 3.

Authors

Muhammad Arshad¹, Biruk A Feyissa², Lisa Amyot³, Banyar Aung⁴, Abdelali Hannoufa⁵

Affiliations

¹ Agriculture and Agri-Food Canada, 1391 Sandford Street, London, Ontario N5 V 4T3, Canada. Electronic address: Muhammad.Arshad@agr.gc.ca.
² Agriculture and Agri-Food Canada, 1391 Sandford Street, London, Ontario N5 V 4T3, Canada; Biology Department, University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada. Electronic address: Biruk.Feyissa@agr.gc.ca.
³ Agriculture and Agri-Food Canada, 1391 Sandford Street, London, Ontario N5 V 4T3, Canada. Electronic address: Lisa.Amyot@agr.gc.ca.
⁴ Agriculture and Agri-Food Canada, 1391 Sandford Street, London, Ontario N5 V 4T3, Canada. Electronic address: banyae.ong@gmail.com.
⁵ Agriculture and Agri-Food Canada, 1391 Sandford Street, London, Ontario N5 V 4T3, Canada; Biology Department, University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada. Electronic address: Abdelali.Hannoufa@agr.gc.ca.

PMID: 28330556
DOI: 10.1016/j.plantsci.2017.01.018

Abstract

Alfalfa (Medicago sativa) is an important forage crop that is often grown in areas that frequently experience drought and water shortage. MicroRNA156 (miR156) is an emerging tool for improving various traits in plants. We tested the role of miR156d in drought response of alfalfa, and observed a significant improvement in drought tolerance of miR156 overexpression (miR156OE) alfalfa genotypes compared to the wild type control (WT). In addition to higher survival and reduced water loss, miR156OE genotypes also maintained higher stomatal conductance compared to WT during drought stress. Furthermore, we observed an enhanced accumulation of compatible solute (proline) and increased levels of abscisic acid (ABA) and antioxidants in miR156OE genotypes. Similarly, alfalfa plants with reduced expression of miR156-targeted SPL13 showed reduced water loss and enhanced stomatal conductance, chlorophyll content and photosynthetic assimilation. Several genes known to be involved in drought tolerance were differentially expressed in leaf and root of miR156 overexpression plants. Taken together, our findings reveal that miR156 improves drought tolerance in alfalfa at least partially by silencing SPL13.

Keywords: Alfalfa; Drought; Gene expression; SPL; Stomata; miR156.

MeSH terms

Abscisic Acid / metabolism
Antioxidants / metabolism
Dehydration / genetics
Gene Expression Regulation, Plant / genetics
Gene Expression Regulation, Plant / physiology
Gene Silencing / physiology*
Medicago sativa / genetics
Medicago sativa / physiology*
MicroRNAs / physiology*
Plant Stomata / physiology
Plant Transpiration / genetics
Plant Transpiration / physiology

Substances

Antioxidants
MicroRNAs
Abscisic Acid