Assessing the potential of exogenous caffeic acid application in boosting wheat (Triticum aestivum L.) crop productivity under salt stress

Caffeic acid (CA) is known as an antioxidant to scavenge reactive oxygen species (ROS), but the underlying mechanism of mediation of plant salt tolerance against various abiotic stresses by caffeic acid is only partially understood. A field experiment (120 days duration) was conducted to investigate the protective role of caffeic acid under a high saline medium (EC 8.7 dS m-1 and textural class: sandy loam) in two wheat genotypes (FSD -08 and Zincol-16). Two levels of caffeic acid (50 μM and 100 μM) were applied exogenously in combination with the salinity stress and results revealed that salt alleviation is more prominent when caffeic acid was applied at the rate of 100 μM. Under saline conditions, wheat genotypes show poor fresh and dry matter accumulation, chlorophyll contents, relative water contents (RWC), membrane stability index (MSI) and activities of antioxidant enzymes and increased uptake of Na+ ions. However, wheat genotype FSD-08 eminently responded to caffeic acid application as compared to wheat genotype Zincol-16 as demonstrated by higher growth indicators, RWC, MSI, activities of antioxidant enzymes, accumulation of mineral ions in grain along with yield attributes. In addition, caffeic acid also mitigated salt-induced oxidative stress malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents as well as significantly reduced Na+ uptake. It can be concluded that caffeic acid-induced salinity tolerance in wheat is attributed to improved plant water relations, K+ uptake, yield contents and activities of antioxidant stress enzymes.

Effects of Osmotic Stress Induced by Polyethylene Glycol (Peg) 6000 and Mannitol on Seed Germination and Seedling Growth of Durum Wheat

Seed germination is generally the critical step in seed establishment and thus the determination of successful crop production. This study was focused at examination of the biochemical and germination parameters effected by low water potential which was generated by polyethylene glycol (PEG) 6000 and mannitol, related to drought stress and growth of Waha durum wheat genotype. Two tests were carried out in a growth chamber; the first comprises seed germination into Petri dishes in the presence of different concentrations of the two osmoticums (0, 5, 10, 15 and 20 % of PEG6000 and mannitol). The second test was carried out in nutrient solution BD medium. Our results shows that Both PEG -6000 and mannitol reduced germination. Therefore, a rapid increase was observed in the rate of germination both for the control plants and the plants subjected to a concentration of 5 g/L and 10 g/L and changes in proportion to the time. For the concentration of 15 g/L and 20 g/L, this phase is very short, which explains the reduced germination rate due to the inhibitory effect of the two osmoticums on germination. In this study, PEG-6000 treatments resulted in an increase of some proteins and a decrease of others. Waha displayed 12 bands for control plants, 40 bands for PEG-6000 stressed plants (all treatments) and 35 bands for mannitol treatments.

Different induction of biogenic amine accumulation during cold acclimation in Triticeae genotypes with varying freezing tolerance

The appropriate timing of the accumulation of biogenic amines is very important during cold acclimation due to their direct protective role and their involvement in the signaling processes. The time course of changes in the amount of six of them was compared during a 3-week acclimation period in a freezing tolerant and a sensitive genotype of rye, barley and wheat. In general, a greater and faster cold-induced increase in biogenic amine content was observed in the tolerant genotypes of the three species compared to the sensitive ones. This change was very quick in the case of putrescine, spermidine and cadaverine reaching a maximum after three days in the freezing-tolerant rye genotype. There was a continuous increase in the spermine and tyramine contents during the whole acclimation period in the tolerant wheat genotype while nearly constant levels were detected in the sensitive one. The amount of these two amines exhibited a positive correlation with the level of freezing tolerance in each of the five sampling points. Based on the correlations, a coordinated adjustment of the level of the six studied biogenic amines occurred during the acclimation period which could contribute to the efficient adaptation to cold. In addition, the earlier induction of the biogenic amine accumulation in the freezing tolerant genotypes may contribute to their better cold acclimation.

Biotechnology for the production of wheat-rye hybrids (primary triticale)

Durum wheat and rye hybrids were obtained using in vitro germ culture. The influence of the durum wheat genotype (♀) on the hybridization performance was revealed, which is due to the presence of genes that inhibit crossbreeding.

Study of salt tolerance in wheat varieties through growth and development approaches

Wheat is one of the most important food crops cultivated in India that considered as moderately sensitive to salinity stress. Present study was conducted to evaluate the growth and developmental response of wheat varieties to salt stress using hydroponics technique. Four wheat genotypes i.e. two durum (HI 8713 and MACS 4028) and two bread wheat (KRL 99 and KRL 210) were selected to study their response under control (best available water) and extreme saline environment (ECiw - 10 dS m-1). Using root length as an index of tolerance, KRL 99 was identified as the most tolerant genotypes which showed 35.67 % reduction in root length under saline environment, whereas other showed higher reduction in root length i.e. 41.78% in KRL 210, 50.68% in MACS 4028 and 78.61% in HI 8713, respectively. Similar results were also noted for shoot length. Under saline condition, higher protein accumulation was recorded in MACS 4028 and HI 8713, whereas KRL 210 showed the less increase (42.5%). All the studied genotypes also showed differential protein profiling banding pattern. The present study concluded that durum wheat genotype also have some potential to survive under saline condition based on growth parameters.