Heterologous codA Gene Expression Leads to Mitigation of Salt Stress Effects and Modulates Developmental Processes.

Transgenic tobacco plants overexpressing the choline oxidase gene from A. globiformis showed an increase in resistance at the level of primary and secondary biosynthesis of metabolites, removing the damage characteristic of salinity and stabilizing the condition of plants. We used 200 mM NaCl, which inhibits the growth of tobacco plants at all stages of development. Leaves of transgenic and wild-type (WT) plants Nicotiána tabácum were used for biochemical, cytological and molecular biological analysis. However, for transgenic lines cultivated under normal conditions (without salinity), we noted juvenile characteristics, delay in flowering, and slowing down of development, including the photosynthetic apparatus. This caused changes in the amount of chlorophyll, a delay in the plastid grana development with the preservation of prolamellar bodies. It also caused changes in the amount of sugars and indirectly downstream processes. A significant change in the activity of antioxidant enzymes and a change in metabolism is probably compensated by the regulation of a number of genes, the expression level of which was also changed. Thus, the tolerance of transgenic tobacco plants to salinity, which manifested itself as a result of the constitutive expression of codA, demonstrates an advantage over WT plants, but in the absence of salinity, transgenic plants did not have such advantages due to juvenilization.

Unexpected Effects of Sulfate and Sodium Chloride Application on Yield Qualitative Characteristics and Symmetry Indicators of Hard and Soft Wheat Kernels.

The heterogeneity of grain quality can lead to limited predictability of qualitative and quantitative characteristics of the wheat yield, especially with an increase in the importance of drought and salinity caused by climate change. This study was undertaken with the aim of creating basic tools for phenotyping and assessing the sensitivity of genotypes to salt effects at the level of some wheat kernel attributes. The study considers 36 variants of the experiment, including four wheat cultivars-Zolotaya, Ulyanovskaya 105, Orenburgskaya 10, Orenburgskaya 23; three treatment variants-control (without salt) and two salts exposure (NaCl at a concentration of 1.1 g L-1 and Na2SO4 at a concentration of 0.4 g L-1); as well as three options for the arrangement of kernels in a simple spikelet-left, middle, and right. It has been established that the salt exposure had a positive effect on the percentage of kernel fulfilling in the cultivars Zolotaya, Ulyanovskaya 105, and Orenburgskaya 23 compared to control. The kernels of the Orenburgskaya 10 variety matured better in the experiment with Na2SO4 exposure, while the control variant and NaCl gave the same effect. When exposed to NaCl, significantly greater values of weight, transverse section area, and transverse section perimeter of the kernel were noted in the cv Zolotaya and Ulyanovskaya 105. Cv Orenburgskaya 10 responded positively to the use of Na2SO4. This salt caused an increase in the area, length, and width of the kernel. The fluctuating asymmetry of the left, middle, and right kernels in the spikelet was calculated. In the cv Orenburgskaya 23 the salts affected only the kernel perimeter among parameters examined. The indicators of the general (fluctuating) asymmetry were lower in the experiments with the use of salts, i.e., kernels were more symmetrical than in the control variant, both for the cultivar as a whole and when compared taking into account the kernel location in spikelet. However, this result was unexpected, since salt stress inhibited a number of morphological parameters: the number and average length of embryonic, adventitious, and nodal roots, flag leaf area, plant height, dry biomass accumulation, and plant productivity indicators. The study showed that low concentrations of salts can positively affect the fulfilling of kernels (the absence of a cavity inside the kernel) and the symmetry of the left and right sides of the kernel.

Bread Wheat in Space Flight: Is There a Difference in Kernel Quality?

Planning long-term space flights necessarily includes issues of providing food for the crew. One of the areas of research is the development of technologies for independent production of food by the crew. Extensive research on lettuce has confirmed that the "space production" of lettuce is not inferior to that on Earth, even in the absence of gravity, but the same deep understanding of the quality of grain crops has not yet been achieved. Therefore, the goal of our work is to establish whether the conditions for growing wheat in outer space without gravity affect the weight and basic parameters of the grain, and whether this leads to increased asymmetry of the kernel and distortion of the starch composition. The objects of the study were wheat (Triticum aestivum L.) kernels of the Super Dwarf cultivar. Of which, 100 kernels matured in outer space conditions in the Lada growth chamber on the International Space Station (ISS), and 85 kernels of the control wheat grown in a similar growth chamber under terrestrial conditions. It has been established that kernels from ISS have significant differences to a smaller extent in weight, area, length, and width of the kernel. However, the kernels under both conditions were predominantly large (the average weight of a kernel in space is 0.0362 g, and in terrestrial conditions-0.0376 g). The hypothesis that the level of fluctuating asymmetry will increase in outer space was not confirmed; significant differences between the options were not proven. In general, the kernels are fairly even (coefficients of variation for the main parameters of the kernel are within 6-12%) and with a low or very low level of asymmetry. The length of starch granules of type A in filled and puny kernels is significantly greater in kernels from ISS than in the control, and in terms of the width of starch granules B and roundness indices, both experimental variants are the same. It can be assumed that the baking qualities of earthly kernels will be slightly higher, since the ratio of type B starch granules to type A is 5-8% higher than on the ISS. Also, the width of the aleurone layer cells in mature kernels was significantly inferior to the result obtained on Earth. The work proposes a new method for establishing the asymmetry of kernels without a traumatic effect (in early works, it was supposed to study asymmetry in transverse sections of the kernels). Perhaps this will make it possible to further develop a computer scanning program that will determine the level of asymmetry of the wheat fruit.