Genetics aspect of vitamin C (Ascorbic Acid) biosynthesis and signaling pathways in fruits and vegetables crops.

Vitamin C, also known as ascorbic acid, is an essential nutrient that plays a critical role in many physiological processes in plants and animals. In humans, vitamin C is an antioxidant, reducing agent, and cofactor in diverse chemical processes. The established role of vitamin C as an antioxidant in plants is well recognized. It neutralizes reactive oxygen species (ROS) that can cause damage to cells. Also, it plays an important role in recycling other antioxidants, such as vitamin E, which helps maintain the overall balance of the plant's antioxidant system. However, unlike plants, humans cannot synthesize ascorbic acid or vitamin C in their bodies due to the absence of an enzyme called gulonolactone oxidase. This is why humans need to obtain vitamin C through their diet. Different fruits and vegetables contain varying levels of vitamin C. The biosynthesis of vitamin C in plants occurs primarily in the chloroplasts and the endoplasmic reticulum (ER). The biosynthesis of vitamin C is a complex process regulated by various factors such as light, temperature, and plant hormones. Recent research has identified several key genes that regulate vitamin C biosynthesis, including the GLDH and GLDH genes. The expression of these genes is known to be regulated by various factors such as light, temperature, and plant hormones. Recent studies highlight vitamin C's crucial role in regulating plant stress response pathways, encompassing drought, high salinity, and oxidative stress. The key enzymes in vitamin C biosynthesis are L-galactose dehydrogenase (GLDH) and L-galactono-1, 4-lactone dehydrogenase (GLDH). Genetic studies reveal key genes like GLDH and GLDH in Vitamin C biosynthesis, offering potential for crop improvement. Genetic variations influence nutritional content through their impact on vitamin C levels. Investigating the roles of genes in stress responses provides insights for developing resilient techniques in crop growth. Some fruits and vegetables, such as oranges, lemons, and grapefruits, along with strawberries and kiwi, are rich in vitamin C. Guava. Papaya provides a boost of vitamin C and dietary fiber. At the same time, red and yellow bell peppers, broccoli, pineapple, mangoes, and kale are additional sources of this essential nutrient, promoting overall health. In this review, we will discuss a brief history of Vitamin C and its signaling and biosynthesis pathway and summarize the regulation of its content in various fruits and vegetables.

Microsatellite-based diversity analysis and the development of core-set germplasm in Pakistani barley lines.

Illustrating the population structure and genetic diversity in selected germplasm resources (after three year multi locations trials) plays a key role which directly utilize the selection of lines in a population for accumulative trait breeding in crops. In order to further understand, the structure of population and genetic variability, we explored 100 selected lines, cultivated for three consecutive years (2016-2019) in swat, University of Malakand, Khyber Pakhtunkhwa Pakistan and Provinces of China (Chongqing and Beijing) with 33 mapped SSR markers. The integrated population structure analysis in a core of hundred germplasm with Pakistani origin with three approved commercial barley cultivars have strong stratification that allowed their division into four major subpopulations (i.e. PI, PII, PIII and PIV) and an admixture subpopulation, with 52, 9, 15 and 27 germplasm respectively. A total of 133 alleles were identified with mean value of 0.80 Polymorphic information content. The number of alleles detected by the system varied from two alleles amplified to as six with an average of 4.03 per SSR marker pair. The gene diversity ranged from 0.56 to 0.98 with an average of 0.82 in selected germplasm resources. Based on the SSR data, the 100 selected germplasm with three cultivars were classified into four main phylogenetic Linages (LI, LII, LIII and LIV) which corresponded to the phylogenic grouping in genotypes. We assembled a core set of 20 barley genotypes (~1/5 of original population size) to sustain sufficient mapping of SSR marker with Phenotype, in which we proposed four SSR markers, Bmac0040, Bmac0134, Bmag0125 and Bmag0211 for malt gene and marker (Bmac0399) for tolerance to salinity gene, which will be applicable for marker assisted breeding in barley gene resources.