Kartseva Tania, Dobrikova Anelia, Kocheva Konstantina, Alexandrov Vladimir, Georgiev Georgi, Brestič Marián, Misheva Svetlana
Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia, Bulgaria.
Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia, Bulgaria.
Plants (Basel). 2021 Mar 5;10(3):493. doi: 10.3390/plants10030493.
Strategies and coping mechanisms for stress tolerance under sub-optimal nutrition conditions could provide important guidelines for developing selection criteria in sustainable agriculture. Nitrogen (N) is one of the major nutrients limiting the growth and yield of crop plants, among which wheat is probably the most substantial to human diet worldwide. Physiological status and photosynthetic capacity of two contrasting wheat genotypes (old Slomer and modern semi-dwarf Enola) were evaluated at the seedling stage to assess how N supply affected osmotic stress tolerance and capacity of plants to survive drought periods. It was evident that higher N input in both varieties contributed to better performance under dehydration. The combination of lower N supply and water deprivation (osmotic stress induced by polyethylene glycol treatment) led to greater damage of the photosynthetic efficiency and a higher degree of oxidative stress than the individually applied stresses. The old wheat variety had better N assimilation efficiency, and it was also the one with better performance under N deficiency. However, when both N and water were deficient, the modern variety demonstrated better photosynthetic performance. It was concluded that different strategies for overcoming osmotic stress alone or in combination with low N could be attributed to differences in the genetic background. Better performance of the modern variety conceivably indicated that semi-dwarfing () alleles might have a beneficial effect in arid regions and N deficiency conditions.
在营养条件欠佳情况下提高耐胁迫能力的策略及应对机制可为可持续农业制定选择标准提供重要指导。氮（N）是限制作物生长和产量的主要养分之一，其中小麦可能是全球人类饮食中最重要的作物。在幼苗期评估了两种截然不同的小麦基因型（古老的Slomer和现代半矮秆Enola）的生理状态和光合能力，以评估氮供应如何影响植物的渗透胁迫耐受性及在干旱期存活的能力。显然，两个品种中较高的氮投入有助于在脱水情况下表现更佳。与单独施加胁迫相比，较低的氮供应与水分剥夺（聚乙二醇处理诱导的渗透胁迫）相结合导致光合效率受到更大损害和更高程度的氧化胁迫。古老的小麦品种具有更好的氮同化效率，并且也是在氮缺乏情况下表现更佳的品种。然而，当氮和水都缺乏时，现代品种表现出更好的光合性能。得出的结论是，单独或与低氮结合克服渗透胁迫的不同策略可归因于遗传背景的差异。现代品种表现更佳可能表明半矮秆（）等位基因在干旱地区和氮缺乏条件下可能具有有益作用。
