Morphological, physiological and biochemical aspects of osmopriming‐induced drought tolerance in lentil

Abstract

Lentil (Lens culinaris Medik.) is an important grain legume crop, mostly grown in semi‐arid environments and often faces intermittent drought spells during different growth stages, which severely hamper its yield. This study, comprising of three separate experiments, was conducted to evaluate the potential of seed priming with CaCl2 in improving drought tolerance in lentil. In the first experiment, lentil seeds were hydroprimed (water) or osmoprimed with 0.5 and 1% CaCl2; while non‐primed seeds were taken as control. In the second and third experiments, lentil seeds were subjected to pre‐optimized osmopriming (1% CaCl2) and hydropriming followed by surface drying or re‐drying of primed seeds to original weight. The first two experiments were conducted in petri plates, while, in experiment 3, seeds were planted in plastic pots containing peat moss, maintained at 75% water holding capacity (WHC; well‐watered) or 50% WHC (water deficit). Hydropriming and osmopriming improved seed germination, seedling growth, biomass production, chlorophyll intensity, sugar accumulation and reduced the oxidative stress in lentil under water deficit. However, osmopriming (1% CaCl2) was more effective than the hydropriming in improving the lentil growth, biomass production, Ca accumulation and sugar metabolism under both well‐watered and water deficit conditions. Seed surface drying, after priming, was more beneficial in improving the lentil performance, under both well‐watered and water deficit conditions, than re‐drying to original weight. Osmopriming (1% CaCl2) increased the seeding dry weight (67%), SPAD value (140%), leaf Ca concentration (56%), α‐amylase activity (55%), total soluble sugars (48%) and reduced malanodialdehyde content (35.9%) and total antioxidant activity (29.2%) than un‐primed seeds under water deficit. In conclusion, osmopriming improved the lentil performance under optimal and water deficit conditions through early and synchronized emergence, better sugar and Ca accumulation which reduced the oxidative damage and resulted in better seedling growth and biomass production.

Seed germination and physiological responses of quinoa to selenium priming under drought stress

“…The results of the present study showed that with increasing drought stress caused by PEG, germination percentage and germination rate have a decreasing trend (Fig 1 and 2). Drought stress disrupts metabolism due to low amylase activity, resulting in significant inhibition of seedling germination and growth (Farooq et al 2020). Increasing the PEG concentration significantly reduced cottonseed germination and germination rate caused by negative regulation in physiological mechanisms and inhibited seed water absorption (Bai et al 2020).…”

Melatonin improves the germination rate of cotton seeds under drought stress by opening pores in the seed coat

“…Previous studies have shown that the accumulation of ABA is closely related to the generation of ROS; specifically, when the accumulation of ABA was lower, the formation of hydrogen peroxide (H 2 O 2 ) reduced accordingly ( Liu et al, 2010 ; Ye et al, 2011 ). Drought stress negatively regulates metabolism due to low α-amylase activity, leading to a significant inhibition of seed germination and seedling growth ( Farooq et al, 2020 ). The accumulation of osmoregulatory substances, such as proline, soluble sugar, and soluble protein, which can reduce the water potential and enhance the water absorption capacity of cells, ensures normal plant metabolism and improves drought resistance ( Zhang et al, 2015a ; Zhang et al, 2015b ).…”

How does water and salt stress affect the germination and initial growth of Brazilian soya bean cultivars?

“…Several studies have shown that shoot is more likely to be affected by abiotic stresses than other traits (Patanè, Saita, & Sortino, 2013;Steiner et al, 2017;Shahi et al, 2015;Farooq et al, 2020).…”

“…These two abiotic stresses initially affect plants in a similar manner, mainly due to the reduction in the water potential of the solution. However, subsequently, the phytotoxic effects of salts on the functions of cell membranes and cell walls may affect the water potential of cytosol and cell extensibility, and both seed germination and seedling growth may be negatively affected (Acosta-Motos et al, 2017;Farooq et al, 2020). Therefore, drought and salt tolerance testing in initial stages of plant growth is important because the seed with more rapid germination under water restriction or salinity conditions may be expected to achieve a rapid seedling establishment, resulting in higher yields.…”