Physiological, Biochemical, and Agronomic Trait Responses of Nigella sativa Genotypes to Water Stress

Abstract

Water stress may affect the growth, physiology, morphology, biochemistry, and productivity of Nigella sativa (black cumin), a medicinal and aromatic plant. Measuring these parameters under various irrigation regimes could provide useful information for successful genotype selection and breeding. Therefore, these agronomically significant features were evaluated in ten black cumin genotypes (Afghanistan, Pakistan, Syria, India, Arak, Isfahan, Semirom, Shahreza, Shahrekord, and Mashhad) under three irrigation regimes (40% (I1), 60% (I2), and 80% (I3) of permissible moisture discharge) during the 2017 to 2018 growing seasons. Water stress was shown to increase the levels of carotenoids (Cars), proline, total soluble carbohydrates (TSC), malondialdehyde (MDA), hydrogen peroxide (H2O2), catalase (CAT), and ascorbate peroxidase (APX) activities but reduced the relative water content (RWC) and chlorophyll content. The highest increases in Cars, TSC, proline, CAT, and APX were noted in the Arak, Isfahan, Semirom, Shahreza, Shahrekord, and Mashhad genotypes under the I3 water regime, respectively. At the same time, the lowest decrease was observed in chlorophyll, H2O2, and relative water content (RWC) in Semirom. According to the stress susceptibility index, the most resistant genotypes were Shahrekord under I2 and Semirom under I3. These data demonstrate that the irrigation regimes affected the physiological, biochemical, and morphological features of black cumin both qualitatively and quantitatively, although the impact varied depending upon the genotype, irrigation regime, and traits. As such, the results presented represent valuable information with which to inform future selection and breeding programs for drought-tolerant black cumin. This is of particular significance considering global climate change.

Foliar Application of Nano-Silicon Improves the Physiological and Biochemical Characteristics of ‘Kalamata’ Olive Subjected to Deficit Irrigation in a Semi-Arid Climate

“…Water stress reduced the leaf's relative water content (RWC) in both years, but the application of nSi improved the RWC exponentially with increased concentration. Similar results were reported on faba beans [53], wheat [70], plums [81], and olives [13,82]. Increased level of ABA-induced stomatal closure had eventually increased RWC [83].…”

“…Drought stress in olives is often associated with increased cellular levels of oxidative stress markers of lipids such as MDA and H 2 O 2 [6]. When an imbalance between reactive oxygen species (ROS) production and the antioxidant defense system occurs, increased cellular membrane damage and electrolyte leakage occur [53,83]. It was also reported that when drought-stressed olive trees were re-watered, they still exhibited higher levels of H 2 O 2 , suggesting that this drought/wet rhythm is a possible means to keep the plant's antioxidative system on alert.…”

“…A large number of genes are activated by stress, and several Si-produced proteins that participate in biochemical pathways lead to the enhancement of stress tolerance [47]. The application of nano-silicon (nSi) has been suggested to enhance plant tolerance to drought stress by reducing the production of reactive oxygen species (ROS) in barley, wheat, faba bean, feverfew, strawberry, Mahaleb cherry, and mango [34,[48][49][50][51][52][53][54]. The primary mechanisms of Si-mediated abiotic stress reduction include plant antioxidant system activation, co-precipitation and immobilization of toxic metal ions in the growth medium, and metal absorption and separation within the plants [55][56][57][58][59][60][61][62][63][64][65][66][67][68].…”

Salicylic Acid Stimulates Defense Systems in Allium hirtifolium Grown under Water Deficit Stress

“…The role of SOD in a plant’s tolerance to water deficit during oxidative stress has been detected to be of great importance; this subject has been reported by many researchers [ 35 ]. Our results support those of many other authors that have reported that, with the increasing intensity of drought stress, SOD activity increases [ 14 , 36 ]. Another important antioxidant enzyme that plays a vital role in the breakdown and inhibition of hydrogen peroxide and its conversion to water and oxygen is the enzyme POD [ 29 ].…”

Different Seasonal Collections of Ficus carica L. Leaves Diversely Modulate Lipid Metabolism and Adipogenesis in 3T3-L1 Adipocytes

“…Nevertheless, contradictory results are present, probably due not only to the lack of standardization but also to the high variability in the phytoconstituents. Both these parameters can be influenced by diverse factors such as different preparations of the plant extracts, plant harvesting seasonality, drought stress and soil conditions [ 23 , 24 , 25 ].…”