Physiological responses and expression of sugar associated genes in faba bean (Vicia faba L.) exposed to osmotic stress

Emna Ghouili; Khaled Sassi; Moez Jebara; Yassine Hidri; Rim Nefissi Ouertani; Yordan Muhovski; Salwa Harzalli Jebara; Mohamed El Ayed; Souhir Abdelkarim; Oumaima Chaieb; Selim Jallouli; Fatma Kalleli; Mahmoud M'hamdi; Fatma Souissi; Ghassen Abid

doi:10.1007/s12298-021-00935-1

Physiological responses and expression of sugar associated genes in faba bean (Vicia faba L.) exposed to osmotic stress

Physiol Mol Biol Plants. 2021 Jan;27(1):135-150. doi: 10.1007/s12298-021-00935-1. Epub 2021 Jan 29.

Authors

Affiliations

¹ Laboratory of Legumes, Centre of Biotechnology of Borj Cedria, BP 901, 2050 Hammam-Lif, Tunisia.
² Laboratory of Agronomy, National Agronomy Institute of Tunisia (INAT), University of Carthage, Avenue Charles Nicolle, BP 43, 1082 Tunis-Mahrajène, Tunisia.
³ Laboratory of Integrated Olive Production, Olive Tree Institute, BP 208, 1082 Tunis-Mahrajène, Tunisia.
⁴ Laboratory of Plant Molecular Physiology, Centre of Biotechnology of Borj Cedria, BP 901, 2050 Hammam-Lif, Tunisia.
⁵ Department of Life Sciences, Walloon Agricultural Research Centre, Chaussée de Charleroi, BP 234, 5030 Gembloux, Belgium.
⁶ Laboratory of Bioactive Substances, Centre of Biotechnology of Borj Cedria, BP 901, 2050 Hammam-Lif, Tunisia.
⁷ Department of Horticultural Sciences and Vegetable Crops, High Institute of Agronomy of Chott Mariem, University of Sousse, 4042 Sousse, Tunisia.

Abstract

Faba bean (Vicia faba L.) is the major food legume crop in Tunisia. However, its growth and yield is strongly affected by water-limited environments. In this study, osmotic stress exhibited a negative effect on Bachar and Badii cultivar. Nevertheless, the deteriorating effects of osmotic stress were relatively low on studied parameters of Bachar due to its better efficiency to reduce oxidative damage by increasing enzymatic activities such as catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX), accumulation of total chlorophyll (Chlt), soluble sugars and leaf relative water content (RWC). GC-MS analysis determined a total of 11 soluble carbohydrates induced by osmotic stress and differentially accumulated in the both cultivars. Bachar showed elevated levels of mannose, glucose, galactose, ribose, rhamnose and myo-inositol which might help to maintain osmotic adjustment, membranes and proteins protection from the damaging effect of reactive oxygen species. Sugar metabolism related genes (VfNINV3, VfPHS2, VfFRK4, VfHXK1, VfGPI1, VfSTP1.1, VfpGlcT1.1, VfSTP5.1, VfpGlcT1.2, VfSWEET2.1, VfVINV2, VfSUS1, VfPGM1, VfSUT1.1, VfGPT1, VfSPS1, VfSPP1, VfPHS1, VfSUT4.1 and VfTMT1.1) were differentially expressed in both cultivars demonstrating their important roles in sugar accumulation. Most of these genes were upregulated in the leaves of Bachar under moderate and severe stress, which could lead to increase glycolysis and tricarboxylic acid cycle in order to accelerate energy production, necessary to increase osmotic regulation and consequently enhancing the osmotic stress tolerance in that cultivar. Overall, sugars accumulation ability can be used as a useful indicator for the osmotic stress tolerant potential in faba bean breeding programs.

Supplementary information: The online version contains supplementary material available at (10.1007/s12298-021-00935-1).

Keywords: Faba bean; GC–MS; Gene expression; Osmotic stress; Sugar metabolism; qRT-PCR.