Methyl jasmonate modulation reduces photosynthesis and induces synthesis of phenolic compounds in sweet potatoes subjected to drought

Abstract

Sweet potato [Ipomoea batatas (L.) Lam.] has wide adaptability to different climatic conditions. However, its yield can be affected by prolonged periods of drought. Application of exogenous jasmonates can modulate several physiological and biochemical processes, improving plant tolerance to abiotic stress. This study sought to evaluate the role of exogenous application of methyl jasmonate (MeJA) in attenuating the adverse effects of drought stress by physiobiochemical analyses and their impact during the early initiation of tuberous roots. The experimental design was completely randomized and arranged in a 2 × 2 factorial, comprised of two concentrations of a MeJA plant regulator [without (0 µmol•L-1) and with (13 µmol•L-1) application] and two water regimes (optimum and drought conditions, corresponding to a field capacity of 100 and 40%, respectively). Plants treated with MeJA showed a reduction in total leaf area and leaf dry biomass but increased adventitious root dry biomass. In addition, MeJA application in sweet potato plants affected photosynthetic performance and increased and antioxidant phenolic compounds, carotenoids, anthocyanins, and proline. The evaluated response mechanisms showed that the severity of drought was more prominent than the positive effects of MeJA, since the increases on antioxidant pigments and secondary metabolites were not sufficient to mitigate stress caused by drought, which was reflected in the reduced tuberous root production.

Drought tolerance inBrassica napusis accompanied with enhanced antioxidative protection, photosynthetic and hormonal regulation at seedling stage

“…According to our results, we hypothesized that JA has a specific role to adjust stomatal aperture in B. napus plants under drought stress. In addition, the upregulation of JA content in response to drought stress suggests an additional mechanism to the ABA signaling that further counteracts the drought stress effect by closing stomata and lowering transpiration rate in plant as previously reported by several authors (de Ollas & Dodd, 2016; Yoshida et al, 2020). SA has been previously proposed to protect the plants photosynthetic machinery and membrane integrity in response to environmental stresses including drought stress (Sharma et al, 2017).…”

Growth, Development, and Photosynthetic Performance of Two Soybean Lineages in Response to Drought

“…The reduction in leaf water content can result in low turgor pressure, leading to decreased gs and limiting cell expansion (Jaleel et al, 2009), hence causing lessened plant growth and development (Ullah et al, 2017), as observed in the Vx-08-11614 (Figure 2A, 2C-D). Similar results in response to drought were reported in different plant species such as sweet potatoes (YOSHIDA et al, 2020), chili pepper (WIDURI et al, 2020), andcabbage (HAGHIGHI et al, 2020).…”

“…The lower Total Chl and carotenoids contents observed in Vx-08-11614 (Figure 3C, 3D, 6) shows a lower efficiency in light absorption and, consequently, a lower transfer of radiant energy to reaction centers under drought (Rosa et al, 2020), which can negatively impact A. Chlorophyll and carotenoids contents are a key factor in plant photosynthesis and closely reflects the photosynthetic capacity of plants (TALBI et al, 2020). In addition, the lower carotenoids content decreases the protection of the antenna complex from oxidative damage (Lapaz et al, 2020;Yoshida et al, 2020), since these antioxidants scavenge reactive oxygen species (ROS) to protect the photosynthetic apparatus (ROSA et al, 2020). However, Mesquita et al (2020) observed a more pronounced decrease in photosynthetic pigments in the tolerant soybean lineage.…”

The Role of Plant Growth-Promoting Bacteria in Alleviating the Adverse Effects of Drought on Plants

“…The pivotal role of ABA during drought was studied in several plant species like, e.g., rice (Oryza sativa) [85] and oilseed rape (Brassica napus) [95]. Similarly, drought stress causes an increase in the accumulation of another group of plant stress hormones, brassinosteroids that ultimately results in an increased water uptake, improved membrane stability and reduced ion leakage during drought conditions [99,100].…”