Daniel da Silva Gomes

The authors would like to make the following correction to their published paper

Drought is a major factor limiting food production worldwide, especially in the current climate change era. As such, strategies to mitigate drought stress in vegetables, such as radish, are paramount to ensure food security. Among these, the use of signaling molecules, such as the NO donor sodium nitroprusside (SNP), are promising. Thus, we aimed to evaluate the effects of SNP in the mitigation of drought stress and in the root quality of radish. For this, plants were grown under three irrigation regimes: irrigation with 80% WRC (well-watered), one week without irrigation (from 14 to 21 days after sowing (DAS)) with subsequent re-watering with 80% WRC (re-watered), and irrigation restriction from 21 to 28 DAS, without re-irrigation (drought). Plants were then sprayed with 100 µM SNP or water (control), and growth, physiological, and biochemical characteristics were evaluated. Irrigation was the main factor affecting radish growth and quality, with drought strongly decreasing carbon assimilation rate and plant growth, and re-watering not reversing these effects. SNP, in turn, did not affect radish growth, but improved storage root quality by increasing the content of total sugars and vitamin C. SNP was not able to mitigate drought stress effects in photosynthetic capacity and biomass production of radish; however, it improved stress recovery upon re-watering, increasing root dry mass and decreasing electrolyte leakage. Overall, this study provides novel evidence that preharvest SNP application improves radish root quality and stress recovery in a condition-dependent manner, highlighting its potential to enhance crop quality under water-limited conditions.

Radish is a nutrient- and antioxidant-rich root vegetable whose growth is strongly affected by water availability, highlighting the need for strategies to enhance drought tolerance. Methyl jasmonate (MeJa) is a bioregulator involved in plant stress responses. This study evaluated the role of MeJa in alleviating water deficit effects in radish. Plants were maintained under well-watered conditions (80% water retention capacity) or subjected to total irrigation restriction from 15 to 30 days after sowing (DAS). Foliar applications of 100 µM MeJa or water were performed at 7, 14, and 21 DAS. Growth, gas exchange, chlorophyll fluorescence, photosynthetic pigments, relative water content, electrolyte leakage, and storage root quality were assessed. Water deficit reduced relative water content and increased electrolyte leakage, indicating oxidative damage, which impaired growth and gas exchange. MeJa application reduced electrolyte leakage but did not mitigate drought-induced reductions in growth or gas exchange. Notably, water deficit increased sugar, mineral, and antioxidant contents in roots, regardless of MeJa treatment. Overall, although MeJa modulated some stress-related physiological responses, enhancing antioxidant defenses, it was insufficient alone to improve drought tolerance in radish.

The development of orange‐ and purple‐fleshed sweet potato genotypes with high nutritional quality and drought tolerance is paramount in the face of climate changes and exponential human population growth. Therefore, the objective was to select biofortified sweet potato genotypes tolerant to drought. Eight progenies developed by the NEOSC‐UFSC group and one commercial genotype were grown in field and greenhouse conditions with drought periods. In the field trial, the plants were grown with very low rainfall from the 4th to the 13th and from 17th to the 18th weeks after planting (WAP). In the greenhouse trial, irrigation was suspended from the 4th to the 7th and 11th to 14th WAP (drought) or maintained throughout the experiment (control). The production of tuberous roots was evaluated in both trials, while biomass, gas exchanges, chlorophyll fluorescence, chlorophyll index, electrolyte leakage, relative water content, wilting tolerance and post‐harvest attributes were determined in the greenhouse trial. The contents of phenolics and flavonoids did not differ among genotypes, which showed small colour variation in response to drought. Water deficit increased electrolyte leakage and reduced yield in all genotypes, which had different responses to drought, modulating gas exchanges, biomass partitioning, energy allocation and defences. The white‐fleshed FW‐42 and LW‐102 and the purple‐fleshed LP‐115 and LP‐75 were the most productive and the most tolerant to drought stress genotypes. These genotypes also showed higher yield than the global average and the commercial Brazlândia branca, pointing to their great potential to be used under well‐water and drought conditions, providing higher nutritional quality.

Hydrogen peroxide (H₂O₂) plays a central role in responses to salt stress, a major abiotic stress that impacts crop yield worldwide. Despite the evidence that H₂O₂ mitigates salt stress and improves post-harvest quality on several species, its effects on radish were not investigated so far. Thus, the objective of this study was to evaluate the exogenous application of H₂O₂ on salt stress mitigation of radish growth, physiology, and post-harvest quality. For this, radish plants were grown in pots for 30 days, being watered with non-saline (0.31 dS m⁻¹) or saline water (120 mM NaCl, 12.25 dS m⁻¹). Plants were leaf-sprayed weekly with water (control – 0 µM H₂O₂) or H₂O₂ (150 or 1500 µM) solutions. The experimental design was completely randomized in a 3 × 2 factorial scheme (H₂O₂ treatments × salt stress conditions). The growth, physiology (gas exchanges, photochemical efficiency, relative water content, electrolyte leakage, and the contents of chlorophylls and carotenoids), and post-harvest attributes of globular roots (color, anthocyanins, vitamin C, phenolic compounds, and soluble solids) were determined. Salt stress decreased gas exchanges and increased electrolyte leakage, which resulted in stunted radish growth, and increased the contents of antioxidants, such as anthocyanins, soluble solids, and vitamin C, improving globular root quality. Conversely, H₂O₂ did not mitigate salt stress effects on radish growth, photosynthetic capacity, and oxidative damages. Although H₂O₂ increased vitamin C under non-stressed condition, it was decreased under salt stress. Thus, we conclude that H₂O₂ did not mitigate salt stress on radish growth and quality.

The exogenous application of bioregulators, such as salicylic acid (SA), has exhibited promising outcomes in alleviating drought stress. Nevertheless, its impact on culantro (Eryngium foetidum L.) remains unexplored. Thus, the aim of this study was to assess how SA impacts the growth, morphophysiology, and essential oil composition of culantro when subjected to drought. To achieve this, culantro plants were grown under three different watering regimes: well-watered, drought-stressed, and re-watered. Additionally, they were either treated with SA (100 µM) or left untreated, with water serving as the control. SA application did not mitigate the effects of drought in biomass production but increased biomass, leaf number, leaf area, and photosynthetic pigments under well-irrigated and re-watered conditions. After a drought period followed by re-watering, plants recovered membrane integrity independently of SA application. Water stress and the exogenous application of SA also modulated the profile of essential oils. This is the first report about SA and drought affecting growth and essential oil composition in culantro.