Molecular biology and (trans) gene expression technology in plant breeding
Abolfazl Mazandarani; Saeid Navabpour; Ahad Yamchi
Abstract
The main source of protein and micronutrients in wheat grains is the flag leaf and to a lesser extent the lower leaves. As healthy leaves reach the final stage of growth, senescence, they remobilize the nutrients necessary before tissue destruction and death. This experiment was carried out in Golestan ...
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The main source of protein and micronutrients in wheat grains is the flag leaf and to a lesser extent the lower leaves. As healthy leaves reach the final stage of growth, senescence, they remobilize the nutrients necessary before tissue destruction and death. This experiment was carried out in Golestan province, and the Wheat cultivars studied were included Euclide and Antonius. Sampling was carried out from flag leaf, other leaves, stem, and grain at 7 stages, Anthesis, 7, 11, 15, 19, 23, and 27 Day After Anthesis (DAA). The total chlorophyll content in the Antonius cultivar was higher in both flag leaf and other leaves than Euclide cultivar. The expression of TaNAM-B1 and TaSAG12 genes, which have been identified as signaling genes for senescence in wheat, showed results consistent with the results of chlorophyll content in leaves. Increased expression of both genes after anthesis was observed earlier in Euclide cultivar than the Antonius cultivar and had higher expression in most stages. In light of the results, the change in concentrations of Cu, Zn, and Fe in the Euclid cultivar was more in all organs than in Antonius one. Also, given the importance of minerals in the food basket, it can be noted that Euclid cultivar, in which leaf senescence begins earlier and more minerals are stored, can produce grains with higher nutritional value than Antonius cultivar.
Plant molecular physiology & breeding
Saeid Navabpour
Abstract
Barley is an important feed grain in many areas such as Canada, Europe and in the U.S. It has also so important for animal feed and has several other usages such as alcohol industry, malt productive and biomass-fuels. The characteristics of physiological and biochemical events during leaf senescence ...
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Barley is an important feed grain in many areas such as Canada, Europe and in the U.S. It has also so important for animal feed and has several other usages such as alcohol industry, malt productive and biomass-fuels. The characteristics of physiological and biochemical events during leaf senescence either flag leaf or other leaves have been investigated in field-grown barley (Hordeum vulgare cv. Hordea). The traits included grain yield, chlorophyll and protein levels, CO2 assimilation rate, fluorescence, α-tocopherol and carotenoid levels, cellular oxidative level and chloroplast-encoded gene expression. The result showed significant role of flag leaf in grain yield. The chlorophyll and protein levels decline dramatically during senescence particularly in other levels. This result was quite similar for net CO2 assimilation rate and maximal efficiency of PSII photochemistry (Fv/Fm). This suggests that PSII apparatus remains functional in senescent flag leaf. Two main lipid-soluble antioxidant agents (α-tocopherol and carotenoid) showed significant increase particularly in flag leaf at late senescence stage around 25 days after anthesis, the level of lipid and other macromolecular-derived peroxidation has been measured by TBARM assay. The TBARM levels increased gradually during flag leaf and particularly other leaves senescence. The transcript levels of the chloroplast-encoded psbA decrease during senescence especially in other leaves. However, the transcript level was significantly higher in flag leaf leading to high level of photosynthesis capacity at the molecular level.