Optimization of 'on farm' hydropriming conditions in wheat: Soaking time and water volume have interactive effects on seed performance.

Seed priming is a simple and cost effective method to obtain a better plant stand under diverse environmental conditions. The current study was designed to determine the optimal priming duration and water volume for wheat seed. For this experiment, three wheat genotypes with distinct genetic and adaptive backgrounds were chosen. Seeds of each genotype were hydroprimed for 7 durations, i.e. 1, 2, 4, 8, 12, 16, and 20 hours, in three different water volumes, i.e. half, equal, and double volume with respect to seed weight and then surface dried for 1 hour. The control was unprimed (dry) seed. The germination characteristics and seedling vigour potential of hydroprimed seeds were evaluated in the lab by recording several parameters such as germination percentage and speed, seedling growth, and vigour indices at two different temperature levels. The results showed that optimal duration for hydropriming of wheat seed is 12 hours with an equal volume with respect to original seed weight, closely followed by 8 hours with double volume. Reduction in seed performance was observed at 16 and 20 hours priming particularly at double volume treatment. Effect of temperature on seed germination showed improvement in seedling vigour at 25°C when compared to 20°C, although effect on germination percentage was non-significant. Volume of water and priming duration showed significant interactive effects demonstrating that a higher volume can give equivalent results at a shorter duration and vice versa. Another experiment was also conducted to compare the on-farm priming (surface dried seed) with conventional priming (seed re-dried to original moisture) taking 3 potential durations i.e. 8, 12 and 16 hours. Results revealed that both priming methods were statistically at par in terms of germination percentage, while, surface drying resulted in better seedling vigour and speed of germination.

Role of Salicylic Acid in Combating Heat Stress in Plants: Insights into Modulation of Vital Processes.

In the present era of climate change and global warming, high temperatures have increased considerably, posing a threat to plant life. Heat stress affects the biochemistry, physiology and molecular makeup of the plant by altering the key processes, i.e., photosynthesis, respiration and reproduction which reduces its growth and development. There is a dire need to manage this problem sustainably for plant conservation as well as the food security of the human population. Use of phytohormones to induce thermotolerance in plants can be a sustainable way to fight the adversities of heat stress. Phytohormone-induced thermotolerance proves to be a compelling approach to sustainably relieve the damaging effects of heat stress on plants. Salicylic acid (SA) is an essential molecule in biotic and abiotic defense response signal transduction pathways. When supplied externally, it imparts heat stress tolerance to the plants by different means, viz., increased Heat Shock Proteins (HSP) production, Reactive oxygen species (ROS) scavenging, protection of the reproductive system and enhancing photosynthetic efficiency. The effect of SA on plants is highly dependent on the concentration applied, plant species, plant age, type of tissues treated, and duration of the treatment. The present review paper summarizes the mechanism of thermotolerance induced by salicylic acid in plants under heat stress conditions. It includes the regulatory effects of SA on heat shock proteins, antioxidant metabolism, and maintenance of Ca2+ homeostasis under heat stress. This review combines the studies conducted to elucidate the role of SA in the modulation of different mechanisms which lead to heat stress tolerance in plants. It discusses the mechanism of SA in protecting the photosynthetic machinery and reproductive system during high-temperature stress.

Chitosan-Salicylic acid and Zinc sulphate nano-formulations defend against yellow rust in wheat by activating pathogenesis-related genes and enzymes.

Stripe rust instigated by Puccinia striiformis f. sp. tritici causes major yield loss in wheat. In this study, disease resistance was induced in wheat by pre-activation of pathogenesis related (PR) genes using two different nano-formulations (NFs) i.e. Chitosan- Salicylic acid (SA) NFs (CH-NFs) and Zinc sulphate NFs (Zn-NFs). These NFs were synthesized using green approach and were characterized using various techniques. Both NFs effectively controlled stripe rust in wheat genotypes (WH 711 and WH 1123) by significantly increasing activities of phenylalanine ammonia lyase, tyrosine ammonia lyase and polyphenol oxidase enzymes when compared with disease free-control and diseased plants. Total soluble sugar (TSS) level was highest in CH-NF treated plants. TSS was also relatively higher in diseased plants than disease free-control as well as Zn-NF treated plants. Both CH-NFs and Zn-NFs induced the expression of PR genes. In CH-NF treated plants, the relative expression of PR genes was higher on the 3rd day after spraying (DAS) of NFs as compared to diseased and Zn-NF treated plants in both the genotypes. While in case of Zn-NF treated plants, relative expression of PR genes was higher on 5th DAS as compared to diseased and disease free-control plants. Early rise in expression of PR genes due to NF treatments was responsible for disease resistance in both the wheat genotypes as evidenced by a lower average coefficient of infection. These NFs can be synthesized easily with low cost input, are eco-friendly and can be effectively used against yellow rust as well as other wheat diseases.

Genome-Wide Transcriptome Profiling, Characterization, and Functional Identification of NAC Transcription Factors in Sorghum under Salt Stress.

Salinity stress has become a significant concern to global food security. Revealing the mechanisms that enable plants to survive under salinity has immense significance. Sorghum has increasingly attracted researchers interested in understanding the survival and adaptation strategies to high salinity. However, systematic analysis of the DEGs (differentially expressed genes) and their relative expression has not been reported in sorghum under salt stress. The de novo transcriptomic analysis of sorghum under different salinity levels from 60 to 120 mM NaCl was generated using Illumina HiSeq. Approximately 323.49 million high-quality reads, with an average contig length of 1145 bp, were assembled de novo. On average, 62% of unigenes were functionally annotated to known proteins. These DEGs were mainly involved in several important metabolic processes, such as carbohydrate and lipid metabolism, cell wall biogenesis, photosynthesis, and hormone signaling. SSG 59-3 alleviated the adverse effects of salinity by suppressing oxidative stress (H2O2) and stimulating enzymatic and non-enzymatic antioxidant activities (SOD, APX, CAT, APX, POX, GR, GSH, ASC, proline, and GB), as well as protecting cell membrane integrity (MDA and electrolyte leakage). Significant up-regulation of transcripts encoding the NAC, MYB, and WRYK families, NHX transporters, the aquaporin protein family, photosynthetic genes, antioxidants, and compatible osmolyte proteins were observed. The tolerant line (SSG 59-3) engaged highly efficient machinery in response to elevated salinity, especially during the transport and influx of K+ ions, signal transduction, and osmotic homeostasis. Our data provide insights into the evolution of the NAC TFs gene family and further support the hypothesis that these genes are essential for plant responses to salinity. The findings may provide a molecular foundation for further exploring the potential functions of NAC TFs in developing salt-resistant sorghum lines.

Identification and Detection of Bioactive Peptides in Milk and Dairy Products: Remarks about Agro-Foods.

Food-based components represent major sources of functional bioactive compounds. Milk is a rich source of multiple bioactive peptides that not only help to fulfill consumers 'nutritional requirements but also play a significant role in preventing several health disorders. Understanding the chemical composition of milk and its products is critical for producing consistent and high-quality dairy products and functional dairy ingredients. Over the last two decades, peptides have gained significant attention by scientific evidence for its beneficial health impacts besides their established nutrient value. Increasing awareness of essential milk proteins has facilitated the development of novel milk protein products that are progressively required for nutritional benefits. The need to better understand the beneficial effects of milk-protein derived peptides has, therefore, led to the development of analytical approaches for the isolation, separation and identification of bioactive peptides in complex dairy products. Continuous emphasis is on the biological function and nutritional characteristics of milk constituents using several powerful techniques, namely omics, model cell lines, gut microbiome analysis and imaging techniques. This review briefly describes the state-of-the-art approach of peptidomics and lipidomics profiling approaches for the identification and detection of milk-derived bioactive peptides while taking into account recent progress in their analysis and emphasizing the difficulty of analysis of these functional and endogenous peptides.