Improvement Of Photosynthetic Performance Research Articles

Insights into salicylic acid-mediated redox homeostasis, carbohydrate metabolism and secondary metabolite involvement in improvement of photosynthetic performance, enzyme activities, ionomics, and yield in different varieties of Abelmoschus esculentus

Salicylic acid (SA) is a well-known signaling molecule and phenolic plant hormone. However, the optimal concentration of SA required for beneficial effects may vary across different plant species. The objective of this study was to investigate the effects of salicylic acid (SA) on two different varieties of Abelmoschus esculentus (Sakata-713 and Neelam) in order to determine the optimal concentration of SA and its impact on the growth, physiology, and biochemical processes of the plants. We conducted an experiment applying different SA concentrations (0, 10−4, 10−5, 10−6, 10−7 M) at 25 days after sowing (DAS) and evaluated various plant parameters at different stages. To evaluate various parameters sampling was performed at 30 and 45 DAS; yield traits were calculated at 60 DAS. The results indicate that SA application increased cell division, trichome number, chlorophyll content, photosynthesis, gas exchange traits, and elemental status which further boosted plants growth and yield traits. SA application stimulated activity of several enzymes that participate in carboxylation/decarboxylation homeostasis (carbonic anhydrase), nitrogen metabolism (nitrate reductase), Calvin cycle (Rubisco), TCA cycle (succinate dehydrogenase and fumarase) and secondary metabolism (phenylalanine lyase). A gradual increase in the production of secondary metabolites (total phenol, total flavonoid, anthocyanin) and carbon metabolism (total reducing sugars, starch, glucose, fructose, sucrose) was observed. Notably, SA treatment also played a vital role in maintaining a balanced equilibrium between reactive oxygen species (ROS) and the scavenging system (catalase, peroxidase, superoxide dismutase). Based on our results, the optimal concentration of SA was determined to be 10−5 M, as it yielded the most favourable outcomes among the different concentrations tested. Moreover, when comparing the two varieties of okra, Sakata-713 exhibited a more promising response to SA treatment compared to Neelam.

Improved photosynthetic performance under unilateral weak light conditions in a wide-narrow-row intercropping system is associated with altered sugar transport.

Intercropping improves resource utilization. Under wide-narrow-row maize (Zea mays) intercropping, maize plants are subjected to weak unilateral illumination and exhibit high photosynthetic performance. However, the mechanism regulating photosynthesis under unilateral weak light remains unknown. We investigated the relationship between photosynthesis and sugar metabolism in maize under unilateral weak light. Our results showed that the net photosynthetic rate (Pn) of unshaded leaves increased as the level of shade on the other side increased. On the contrary, the concentration of sucrose and starch and the number of starch granules in the unshaded leaves decreased with increased shading due to the transfer of abundant C into the grains. However, sink loss with ear removal reduced the Pn of unshaded leaves. Intense unilateral shade (40% to 20% normal light), but not mild unilateral shade (60% normal light), reduced grain yield (37.6% to 54.4%, respectively). We further found that in unshaded leaves, Agpsl, Bmy, and Mexl-like expression significantly influenced sucrose and starch metabolism, while Sweet13a and Sut1 expression was crucial for sugar export. In shaded leaves, expression of Sps1, Agpsl, and Sweet13c was crucial for sugar metabolism and export. This study confirmed that unshaded leaves transported photosynthates to the ear, leading to a decrease in sugar concentration. The improvement of photosynthetic performance was associated with altered sugar transport. We propose a narrow-row spacing of 40 cm, which provides appropriate unilateral shade and limits yield reduction.

Improvement of Photosynthetic Performance by Acetic Acid to Enhance Drought Tolerance in Common Bean (Phaseolus vulgaris)

Improvement of Photosynthetic Performance by Acetic Acid to Enhance Drought Tolerance in Common Bean (Phaseolus vulgaris)

Photosynthates competition within the boll–leaf system is alleviated with the improvement of photosynthetic performance during the succession of Xinjiang cotton cultivars

The yield of cotton (Gossypium hirsutum L.) has increased steadily with the release of different cultivars over the years in Xinjiang, China. However, the reasons for this increased yield have been controversial. As the sympodial leaf and boll within the boll–leaf system of cotton develop together, their competition for photosynthates is intense during their growth, which may be an important factor influencing boll weight. Consequently, we speculated that shortening period during which the sympodial leaf and boll develop together, which would alleviate photosynthates competition, might contribute to boll growth during the succession of cotton cultivars. To test this hypothesis, changes in yield characteristics and photosynthetic performance were studied by examining the main cotton cultivars from four breeding eras (1980s, 1990s, 2000s, and 2010s) in the Xinjiang early-maturing cotton region. The results showed that the single boll weight and the number of bolls increased gradually, and the yield increased steadily with cultivar succession. In the boll–leaf system of cotton, the rapid growth period of the sympodial leaves moved forward, thus reducing the time during which the sympodial leaves and bolls developed simultaneously; at the same time, the rapid growth duration of boll was extended during cultivar succession. In addition, the succession of cotton cultivars was accompanied by increased leaf area, increased leaf photosynthetic rate (Pn) after flowering, and an extension of photosynthetic functional duration within the boll–leaf system. Compared with the sympodial leaves, the photosynthetic performance of the main-stem leaves was improved more obviously in the same boll–leaf system. Therefore, during cotton cultivar succession in Xinjiang, the photosynthates competition between sympodial leaf growth and boll development was significantly alleviated within a boll–leaf system with the improvement of photosynthetic performance, which may further extend the rapid growth duration of boll, thus enhancing single boll weight and yield of cotton.