The Effect of Water Stress on the Glucosinolate Content and Profile: A Comparative Study on Roots and Leaves of Brassica oleracea L. Crops

Abstract

Drought is one of the major challenges of global crop production, and its severity is increasing because of climate change. This abiotic stress is an important target for Brassica species, which are generally grown in arid and semi-arid climates. This study was conducted to investigate the effects of water deficit on a set of accessions belonging to the Brassica core collection of the EU H2020 BRESOV project, represented by Brassica oleracea L. crops and Brassica oleracea complex species (n = 9). In particular, the variation in the amount and profile of the glucosinolates (GLSs) compounds was analyzed on the root and the leaf tissues. The plant morphometric traits and GLSs amount and profile were detected for the plants grown in cold greenhouse in Catania (Sicily) during the autumn–winter season for ten weeks. The results showed a wide qualitative and quantitative variation among the Brassica accessions. The GLSs profile varied qualitatively and quantitively among both genotypes and portions of the plants (hypogenous-root and epigeous-leaf). Plants grown under drought stress, for the last two weeks of the growing cycle under consideration, showed a higher amount of GLS in their leaves (190.1 ± 8.9 µmol. g−1 d.w.) compared to their roots (17.3 ± 1.9 µmol. g−1 d.w.). Under water stress conditions, the highest increase in the glucosinolate amount was detected in broccoli (the accession BR1) with 85.4% and in cauliflower (the accession CV1) with 72.8% in the roots and leaves, respectively. Positive correlations were found between the major leaf and root GLSs identified. The selection of chemotypes allows for an important time reduction during the breeding programs after crossing accessions with the specific profiles of glucosinolates.

Unveiling Glucosinolate Diversity in Brassica Germplasm and In Silico Analysis for Determining Optimal Antioxidant Potential

“…Furthermore, the positive correlations between GNA and GBN (r = 0.428) and GNS (r = 0.339), as well as between PRO and GNS (r = 0.397), suggest that these GSLs may participate in similar plant defense mechanisms or metabolic pathways. The positive correlations between GTL and GBB (r = 0.489) and GBS (r = 0.329), and between GNS and GBB (r = 0.347) and GBS (r = 0.322), further support the idea of interconnected GSL metabolism within Brassica species [66,71]. The observed positive correlation between GBB and GBS (r = 0.308) reinforces the notion of a coordinated regulation or shared biosynthetic pathways among different GSLs.…”

“…These findings underscore the intricate network of GSL metabolism in Brassica species, highlighting the potential to develop breeding and genetic engineering strategies aimed at enhancing desirable GSLs for improved plant defense and nutritional value [ 69 ]. Further research is needed to elucidate the underlying mechanisms of these correlations, which could lead to novel approaches to crop improvement [ 71 , 73 ].…”

Abiotic stress-induced secondary metabolite production in Brassica: opportunities and challenges

“…sabellica ) increased the expression of genes associated with glucosinolates, especially aliphatic alkenyl glucosinolates and genes associated with glucosinolate breakdown ( Podda et al., 2019 ). It was also shown that drought stress in Brassica oleracea L. crops influences both qualitative and quantitative changes in GSL content and suggests a possible link between water stress resistance and the accumulation of NGBS ( Ben Ammar et al., 2023 ). They also revealed that the highest increase in the glucosinolate amount was detected in broccoli roots, followed by cauliflower leaves under water stress conditions.…”

The Phytonutrient Content and Yield of Brassica Microgreens Grown in Soilless Media with Different Seed Densities

“…Rocket microgreens had significantly higher glucosinolates when grown in H × 4D and H × 8D (Table 6). The variation of total glucosinolate content in plants is widely recognized and influenced by diverse factors such as environmental conditions, climate, soil nutrient availability, plant location and variety, plant density, and the developmental stage [55]. Reduced moisture content in Hygromix could have induced the glucosinolate concentration in all three microgreens.…”