Abiotic stresses are the major environmental factors that play a significant role in decreasing plant yield and production potential by influencing physiological, biochemical, and molecular processes. Abiotic stresses and global population growth have prompted scientists to use beneficial strategies to ensure food security. The use of organic compounds to improve tolerance to abiotic stresses has been considered for many years. For example, the application of potential external osmotic protective compounds such as proline is one of the approaches to counteract the adverse effects of abiotic stresses on plants. Proline level increases in plants in response to environmental stress. Proline accumulation is not just a signal of tension. Rather, according to research discussed in this article, this biomolecule improves plant resistance to abiotic stress by rising photosynthesis, enzymatic and non-enzymatic antioxidant activity, regulating osmolyte concentration, and sodium and potassium homeostasis. In this review, we discuss the biosynthesis, sensing, signaling, and transport of proline and its role in the development of various plant tissues, including seeds, floral components, and vegetative tissues. Further, the impacts of exogenous proline utilization under various non-living stresses such as drought, salinity, high and low temperatures, and heavy metals have been extensively studied. Numerous various studies have shown that exogenous proline can improve plant growth, yield, and stress tolerance under adverse environmental factors.

Saffron is the world’s most coveted spicy plant that has medicinal value. Currently, due to diverse types of difficulties in growing this plant outdoor, the tendency to produce it indoor has been increased. Optimized indoor conditions for growing saffron plants is not fully determined so far. This study was conducted to investigate the interactive effects of two plant growth regulators (PGRs), including gibberellic acid (GA₃) and γ-aminobutyric acid (GABA) and four light recipes, including white, monochromatic blue, monochromatic red, and a combination of 50% red and 50% blue on the flower yield and phytochemical components (such as crocin, picrocrocin and safranal) in stigmas of indoor-grown saffron. The results showed that exogenous GABA application and combined red and blue LED lights enhanced the performance of saffron flowers in terms of the number of flowers (up to 1.97 per corm) as well as the fresh and dry weight of flowers and stigmas. In saffron, the concentration of three major secondary metabolites is of great importance since it determines its commercial, pharmaceutical quality. GABA induced saffron’s chemical ingredients toward the phytochemicals safranal (up to 5.03%) and picrocrocin (up to 15.8%), while GA₃ induced them toward the carotenoid pigment crocin (up to 25.1%). In conclusion, the application of GABA with a combination of red and blue lights enhanced the production of high-quality stigmas and positively affected the yield of flowers in saffron plants.

Low availability of iron (Fe) in calcareous and saline soils is one of the major causes of diminished production of crops such as wheat. This study investigated the effects of slow-release fertilizers enriched with Fe, on some qualitative and biochemical traits of new wheat (Triticum aestivum L.) cultivar, Narin, under salt stress. For this purpose, a greenhouse experiment was conducted to evaluate different levels of Fe fertilizer application including non-fertilizer application, ferrous sulfate at 10 and 20 mg kg⁻¹, and super-absorbent fertilizer enriched with Fe equivalent 10 and 20 mg kg⁻¹ ferrous sulfate on wheat plants under three levels of salt stress (0, 8, and 12 dS m⁻¹). The fertilizer application improved chlorophyll a, total chlorophyll, soluble sugars, K⁺ concentration, grain Fe content, and 100-grain weight. The salinity increased proline and Na⁺ content in the leaves, causing a considerable decline in the total soluble carbohydrate, 100-grain weight, K⁺/Na⁺ ratio, and protein content of the leaves. The slow-release fertilizer enriched with Fe was more effective in enhancing the grain quality and salt stress tolerance than ferrous sulfate because of raising grain Fe content, soluble sugars, K⁺ concentration, and K⁺/Na⁺ ratio of the leaf. These results suggest that application of the proper type of iron-containing fertilizers, including slow-release fertilizers, and replacing them with common fertilizers would help wheat plants cope with salinity.

One of the crucial issues in developing nations is diminishing the yield gaps. Therefore, accurate yield gap estimation has many real-world uses for increasing crop production. Utilizing comparative performance analysis (CPA) techniques, the yield gap of wheat fields was evaluated in this study. In Varamin, Tehran Province, Iran, data on 104 wheat fields were collected between 2018 and 2020 and every aspect of wheat field management has been documented. The CPA model determines the yield gap’s contributing factors and potential yield. The results of data analysis revealed that the production ranged from 2600 to 7600 kg ha⁻¹. The CPA method predicted a potential yield of 9316 kg ha⁻¹ and found a yield gap of 3748 kg ha⁻¹; this amount was 40.23% of the potential yield. Leaf chlorophyll (29%), irrigation at stem extension (9%), LAI (7.7%), soil salinity (8.2%), field area (16.3%), phosphorus consumption (6%), nitrogen utilized at the stage of tillering (16%), and HI (7.8%) all contributed to the yield gap in the CPA. It has been said that the computed yield in CPA is a potential yield that can be reached. CPA is a cheap and straightforward tool that could identify yield gaps and their causes in a district without the need for costly experiments. Therefore, developing nations with significant efficiency and yield gaps can use these techniques effectively.

Saffron, a valuable spice and industrial crop used in food, pharma, and cosmetics, is propagated only vegetatively via corms due to triploid male sterility