Anti-Salicylic Acid polyclonal antibody

Excess nickel (Ni) concentration in the growing medium severely hampers the plant growth by disturbing oxidative metabolism and nutrient status. The present study was carried out to investigate the individual and interactive effects of Ni toxicity (0.25 mM NiSO4.6H2O) and nutrient deprivation (no-N, no-P, or no-K) on growth, oxidative metabolism, and nutrient uptake in primed and non-primed rice seedlings. Rice seed was primed with distilled water (hydropriming), selenium (5 mg L-1), or salicylic acid (100 mg L-1). The Ni toxicity and deprivation of N, P, or K posed negative effects on the establishment of rice seedlings. The shoot length and fresh biomass were severely reduced by Ni toxicity and nutrient stresses; the minimum shoot growth was recorded for rice seedlings grown under Ni toxicity and no-N stress. The Ni toxicity reduced the root fresh biomass but did not significantly affect the root length of N-deprived seedlings. The rice seedlings with no-P or no-K recorded similar root fresh biomass compared with those grown with sufficient nutrient supply. The Ni toxicity alone or in combination with nutrient stresses triggered the production of reactive oxygen species (ROS) and caused lipid peroxidation in rice seedlings. Among antioxidants, only glutathione reductase and vitamin E were significantly increased by Ni toxicity under different nutrient stress treatments. The Ni toxicity also reduced the concentrations of N particularly in shoot of rice seedlings. The N-deprived (no-N) seedlings recorded maximum Ni concentration in shoot, while K-deprived (no-K) seedlings showed higher Ni concentrations in root. Seed priming with selenium or salicylic acid was effective to alleviate the detrimental effects of Ni toxicity and/or nutrient stresses on rice seedlings. The better growth and greater stress tolerance of primed seedlings was coordinately attributed to lower ROS production, higher membrane stability, strong antioxidative defense system, and maintenance of mineral nutrient status.

Fresh-cut lettuce, stored in modified atmosphere packaging (MAP), is a frequent component of bagged salads. However, even in MAP, fresh-cut lettuce is highly perishable due to non-microbial deterioration manifested by tissue liquefaction. The present study investigated the effects of plant physiology, lettuce processing, storage conditions, and exogenous stimuli on the deterioration of fresh-cut lettuce stored in MAP. Tests were performed on genotypes with a known rate of deterioration after processing. Leaf maturity of slowly deteriorating cultivars was generally negatively correlated with the shelf life, i.e., younger leaves deteriorated more slowly than older leaves. Leaf maturity of rapidly deteriorating cultivars was positively correlated with the shelf life, i.e., younger leaves deteriorated more rapidly than older leaves. The deterioration rate increased with temperature. Larger salad pieces deteriorated slower than smaller pieces and pieces that had additional wounding. Packaged samples of smaller size (less tissue per MAP bag with a constant volume) usually had a slower deterioration rate than larger samples. Reduced humidity in MAP slowed the rate of deterioration, particularly for rapidly deteriorating cultivars. Ethanol and hexanal accelerated the deterioration process of all cultivars in a dose-dependent manner. Sanitization of lettuce with chlorine, or treatments with abscisic acid, methyl jasmonate, salicylic acid, melatonin, or calcium lactate, had no obvious effect on the deterioration rate at the tested concentrations. This work provides insights into factors that need to be optimized to slow the rate of physiological deterioration of fresh-cut salad and identifies the most suitable conditions to reveal genotypic differences among lettuces.