Germinative and Post-Germinative Behaviours of Brassica napus Seeds Are Impacted by the Severity of S Limitation Applied to the Parent Plants

The influence of barley genotype and growing conditions on zinc and cadmium accumulation

Zinc and cadmium accumulation of in plant tissues of barley of the line 999-93 and of its regenerant forms resulting from cell selection was assessed. The scheme of the experiment: 1) control; 2) acidic; 3) cadmium. We used the method of inversion voltammetry to assess the share of zinc and cadmium in plant samples. To assess the share of active and total forms of zinc and cadmium in soil samples collected from root rhizosphere we used the method of atomic absorption spectroscopy. Barley plants accumulated zinc from 0.2 to 79.7 mg∙kg-1 of dry phytomass. The genotype of plants has little influence on zinc accumulation, and plant organs participate in equal measure in zinc accumulation. As for the soil background with cadmium excess, there is a tendency to lessening zinc absorption in all the plant organs, and it is not connected with the plant’s genotype. Unlike zinc, cadmium gets accumulated mostly in the root system. In the control background the share of cadmium in roots was 0.2–0.4 mg∙kg-1; in the acidic one – 0.2–3.6 mg∙kg-1; in the cadmium one – 5.5–9.5 mg∙kg-1. In barley grain grown on soil with excess of cadmium we did not find any IPC excess of cadmium. On backgrounds of the same acidity, the more cadmium concentration grew, the less zinc concentration in grain was, mostly it concerns the original genotype, to a smaller degree it concerns the regenerant line on the selective medium with cadmium and aluminum. Coupling accumulation of zinc and cadmium took place mostly on acidic background, it was characteristic of barley with the original genotype and the regenerant selected in vitro as cadmium-resistant; on control background coupling accumulation is characteristic of aluminum-resistant regenerant. These regenerant genotypes had a tendency to eliminating cadmium and absorbing zinc.

Transgenerational Effects of Salt Stress Imposed to Rapeseed (Brassica napus var. oleifera Del.) Plants Involve Greater Phenolic Content and Antioxidant Activity in the Edible Sprouts Obtained from Offspring Seeds

Previous research has demonstrated that rapeseed sprouts obtained under salinity demonstrate greater phenolic content and antioxidant activity compared to those sprouted with distilled water. This work aimed to test the hypothesis that these effects of salinity may persist into the next generation, so that offspring seeds of plants grown under salt stress may give edible sprouts with increased phenolic content and antioxidant activity. Plants of one rapeseed cultivar were grown in pots with 0, 100 and 200 mM NaCl, isolated from each other at flowering to prevent cross-pollination. Offspring seeds harvested from each salinity treatment were then sprouted with distilled water. We performed the extraction of free and bound phenolic fractions of sprouts and, in each fraction (methanolic extract), we determined the total polyphenols (P), flavonoids, (F), and tannins (T) with Folin-Ciocalteu reagent, the phenolic acids (PAs) by ultra-high-performance liquid chromatographs (UHPLC) analysis, and the antioxidant activity with three tests (2,2-diphenyl-1-picrylhydrazyl-hydrate, DPPH; ferric reducing antioxidant power, FRAP; 2,2'-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid] diammonium salt, ABTS). Individual seed weight was slightly decreased by salinity, whereas germination performance was improved, with a lower mean germination time for salted treatments. No significant differences were observed among treatments for P, F and T, except for bound P, while, in most cases, single PAs (as free, bound and total fractions) and antioxidant activity were significantly increased in salted treatments. Our results open new perspectives for the elicitation of secondary metabolites in the offspring seeds by growing parental plants under stressing conditions, imposed on purpose or naturally occurring.

Advances in Plant Sulfur Research

As an essential nutrient required for plant growth and development, sulfur (S) deficiency in productive systems limits yield and quality. This special issue hosts a collection of original research articles, mainly based on contributions from the 11th International Plant Sulfur Workshop held on 16-20 September 2018 in Conegliano, Italy, focusing on the following topics: (1) The germinative and post-germinative behaviour of Brassica napus seeds when severe S limitation is applied to the parent plants; (2) the independence of S deficiency from the mRNA degradation initiation enzyme PARN in Arabidopsis; (3) the glucosinolate distribution in the aerial parts of sel1-10, a disruption mutant of the sulfate transporter SULTR1;2, in mature Arabidopsis thaliana plants; (4) the accumulation of S-methylcysteine as its γ-glutamyl dipeptide in Phaseolus vulgaris; and (5) the role of ferric iron chelation-strategy components in the leaves and roots of maize, have provided new insights into the effect of S availability on plant functionality. Moreover, the role of S deficiency in root system functionality has been highlighted, focusing on (6) the contribution of root hair development to sulfate uptake in Arabidopsis, and (7) the modulation of lateral root development by the CLE-CLAVATA1 signaling pathway under S deficiency. The role of S in plants grown under drought conditions has been investigated in more detail focusing (8) on the relationship between S-induced stomata closure and the canonical ABA signal transduction machinery. Furthermore, (9) the assessment of S deficiency under field conditions by single measurements of sulfur, chloride, and phosphorus in mature leaves, (10) the effect of fertilizers enriched with elemental S on durum wheat yield, and (11,12) the impact of elemental S on the rhizospheric bacteria of durum wheat contributed to enhance the scientific knowledge on S nutrition under field conditions.