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Soil salinization is a widespread environmental problem that impacts agriculture. Potassium fertilization is often associated with stress mitigation. Aiming to identify the ability of Rhodes grass (Chloris gayana Kunth) to cope with high salt as well as to investigate the potential of K + fertilization to alleviate stress symptoms, we investigated the combined effects of NaCl and KCl on photosynthesis, ion distribution, and growth of two Rhodes grass cultivars, Callide and Reclaimer. Plants were grown under different regimes (0, 200, 400, and 600 mM NaCl + 1 or 10 mM KCl). For Reclaimer, 10 mM KCl induced positive effects in photochemistry under 0 and 200 mM NaCl, as illustrated by fluorescence transients OJIP-bands and JIP-test parameters. However, such improvements did not lead to superior biomass accumulation nor net photosynthesis compared to the corresponding treatments under 1 mM KCl, which may not justify KCl application. In Callide 10 mM KCl induced deleterious effects on photochemistry of plants under low NaCl levels. High salinity (600 mM) induced stress-triggered biomass reduction of up to 70% in both cultivars, but all plants remained photosynthetically active. Exposure of both cultivars to NaCl concentrations equal to or higher than 200 mM triggered response mechanisms such as the ability to accumulate inorganic solutes accounting to osmotic potential, stomata closure, and excretion (up to 70%) of the retained Na + onto the leaf surface irrespective of KCl. Our data reinforce that Rhodes grass is an auspicious forage crop for saline environments and, therefore, in revegetation programs for saline soils pasture in subtropical regions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Drought-tolerant species, such as Setaria viridis, a C 4 model plant, make physiological and biochemical adjustments water limitation and recover from the stress upon its release. We investigated S. viridis (A10.1 accession) responses to continuing osmotic stress. The osmotic stress was imposed using polyethylene glycol (PEG) 8000 (7.5%) for 10 days. Morphological traits and stomatal conductance were measured daily for the 10 days. On days 6 and 10, the following traits were measured separately for root and shoot: relative water content (RWC), osmotic potential (OP), electrolytic leakage (EL), and proline content. qPCR analysis was used to evaluate the expression of five selected genes in roots (SvLEA, SvDREB1C, SvPIP2-1, SvHSP20, and SvP5CS2), and chlorophyll a fluorescence was measured on three key days. The morphological data demonstrated a drastic reduction in shoot biomass as an effect of water deficit caused by the osmotic stress. Shoot biomass reduction could be associated with putative ABA-dependent signaling involved in SvDREB1C expression. Stomatal conductance and photosynthesis were severely affected up until day 6, however, stomatal conductance and some photosynthetic parameters such as F V /F M , ABS/RC, and DI 0 /RC showed total or slight recovery on day 10. Root EL decreased in treated plants suggesting an investment in membrane protection by osmoregulator expression such as dehydrin (SvLEA) and proline (SvP5CS2) genes. Our data suggest that S. viridis exhibited a partial recovery from an imposed and constant osmotic stress within 10 days., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

The objective of this study was to investigate and characterize cowpea (Vigna unguiculata) genotypes for total grain protein content, storage protein fractions (globulin, albumin, prolamin, basic and acid glutelins), and phytate and minerals contents. Eighteen cowpea genotypes were selected. Total grain protein content varied from 21.4% to 29.2%, for BRS Marataoã and Paulistinha genotypes, respectively. The variation in the concentration of each protein fraction was significant (P<0.05) only for glutelins (basic and acid). The genotypes studied exhibited great similarity in the PAGE electrophoretic profile of the grain protein fractions and also in the mineral content. BRS Paraguaçu genotype exhibited higher Zn content than thegenotypes that have been previously recommended for this characteristic. The lowest phytate grain content was observed in four of the 18 genotypes studied, which also exhibited high protein contents. Although the results did not converge to the selection of a few genotypes, some specific differences were detected that which may be further explored. Considering total grain protein, mineral and phytate contents, the genotype Paulistinha revealed a better balance unveiling high grain total protein content, low grain phytate content and more homogeneous mineral composition.

Produced water (PW) is a mixture of formation water and injected water from oil and gas reservoirs, which contain a complex composition of dissolved and particulate organic and inorganic chemicals. High quantities of PW are extracted with the oil, which can be discharged into the environment, re-injected into the wells or treated for reuse. The present study aimed to evaluate the soil ecotoxicity under an irrigation system using treated PW (water-oil separation, sand filter, activated charcoal filter, reverse osmosis) for sunflower production, predicting conditions for PW reuse in the semi-arid region of Brazil. The experiment was conducted in a greenhouse using natural soil in vessels. Water from public water supply was used as control. Soil samples from two production cycles of sunflowers were assessed using ecotoxicity tests with soil invertebrate's species representing macro and mesofaunal groups: Eisenia andrei (earthworms), Folsomia candida (collembolans) and Enchytraeus crypticus (enchytraeids). Leachates samples were evaluated with aquatic ecotoxicity tests to assess the soil retention function. Results showed impact of irrigation with PW in all treatments except reverse osmosis. Significant negative correlations were found among reproduction of soil invertebrates, high Na + concentrations and electrical conductivity. The effects of other contaminants not analyses should not be discarded. It is important to highlight that salinity is not usually included in target values of soil quality. This study reinforces the importance of ecotoxicity tests in predictive and retrospective risk assessment, joining effects of contaminant mixtures or even that contaminants not considered in chemical scope of analysis or legislation., (Copyright © 2019. Published by Elsevier Ltd.)

In this study, we are presenting recommendations to the best agricultural use as well as for plant breeding of three millet cultivars namely ENA1 and ENA2, which have African origin, and BRS1501 originally from India. These cultivars were evaluated for growth, yield and grain quality traits. The morphological traits evaluated in this study indicated that the African genotypes ENA1 and ENA2 are better than the Indian genotype BRS1501 for no-till farming or to produce forage with 15% of crude protein at flowering and at harvest to produce stover (around 7% of crude protein content) for livestock feeding. The BRS1501 cultivar exhibited the highest values for total crude protein, albumins and prolamins, phytate and mineral contents in grains. ENA1 and ENA2 exhibited the highest values of globulin and glutelin contents. The electrophoretic patterns for storage proteins were similar across the three millets cultivars, except for a higher intensity of two glutelin bands with 21 and 24 kDa in BRS1501. Together, the results allow us to recommend BRS1501 for grain production and ENA1 and ENA2 for biomass production.

The grain proteins of barley are deficient in lysine and threonine due to their low concentrations in the major storage protein class, the hordeins, especially in the C-hordein subgroup. Previously produced antisense C-hordein transgenic barley lines have an improved amino acid composition, with increased lysine, methionine and threonine contents. The objective of the study was to investigate the possible changes in the regulation of key enzymes of the aspartate metabolic pathway and the contents of aspartate-derived amino acids in the nontransgenic line (Hordeum vulgare L. cv. Golden Promise) and five antisense C-hordein transgenic barley lines. Considering the amounts of soluble and protein-bound aspartate-derived amino acids together with the analysis of key enzymes of aspartate metabolic pathway, we suggest that the C-hordein suppression did not only alter the metabolism of at least one aspartate-derived amino acid (threonine), but major changes were also detected in the metabolism of lysine and methionine. Modifications in the activities and regulation of aspartate kinase, dihydrodipicolinate synthase and homoserine dehydrogenase were observed in most transgenic lines. Furthermore the activities of lysine α-ketoglutarate reductase and saccharopine dehydrogenase were also altered, although the extent varied among the transgenic lines., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

To assess the severity of oil spills on mangroves, diagnosis of the vegetation health is crucial. Some aspects of photosynthesis such as photochemical efficiency and leaf pigment composition together with the level of oxidative stress may constitute reliable indicators for vegetation health. To test this approach 14 month old Laguncularia racemosa were contaminated with 5 L m(-2) of the marine fuel oil MF-380 and treated with an oil degrading bacterial consortium in microcosms. Contamination resulted in a 20% decrease in shoot dry weight after 128 days. Photochemical efficiency, pigment content, catalase and ascorbate peroxidase remained unchanged. Multivariate ordination of DGGE microbial community fingerprints revealed a pronounced separation between the oil contaminated and the non-contaminated samples. Further studies are necessary before physiological parameters can be recommended as indicators for plant's health in oil polluted mangroves., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Aspartate kinase (AK, EC 2.7.2.4), homoserine dehydrogenase (HSDH, EC 1.1.1.3) and dihydrodipicolinate synthase (DHDPS, EC 4.2.1.52) were isolated and partially purified from immature Chenopodium quinoa Willd seeds. Enzyme activities were studied in the presence of the aspartate-derived amino acids lysine, threonine and methionine and also the lysine analogue S-2-aminoethyl-l-cysteine (AEC), at 1 mM and 5 mM. The results confirmed the existence of, at least, two AK isoenzymes, one inhibited by lysine and the other inhibited by threonine, the latter being predominant in quinoa seeds. HSDH activity was also shown to be partially inhibited by threonine, whereas some of the activity was resistant to the inhibitory effect, indicating the presence of two isoenzymes, one resistant and another sensitive to threonine inhibition. Only one DHDPS isoenzyme highly sensitive to lysine inhibition was detected. The results suggest that the high concentration of lysine observed in quinoa seeds is possibly due to a combined effect of increased lysine synthesis and accumulation in the soluble form and/or as protein lysine. Nitrogen assimilation was also investigated and based on nitrate content, nitrate reductase activity, amino acid distribution and ureide content, the leaves were identified as the predominant site of nitrate reduction in this plant species. The amino acid profile analysis in leaves and roots also indicated an important role of soluble glutamine as a nitrogen transporting compound.

Plants of Zea mays L., Hordeum vulgare L. and Arabidopsis thaliana (L.) Heynh. were grown at different concentrations of nitrogen, as NH 4 NO 3 , and the antioxidant enzyme activities and quantities in the roots, were studied. Maize plants were grown at 1 and 10 mM N for 32 d after germination and their roots were analysed by native PAGE for the isoenzymic profiles of glutathione reductase (GR; EC 1.6.4.2), catalase (CAT; EC 1.11.1.6) and superoxide dismutase (SOD; EC 1.15.1.1) and by spectrophotometric assays for total activity of CAT and GR. Barley and A. thaliana plants were grown at five N concentrations (0.25, 0.5, 1, 10 and 20 mM) for 27 and 26 d, respectively, and the isoenzymic profile of the three enzymes were analysed in their roots. The number of GR isoforms in the three plant species was increased at high N supply compared with low N. In addition, the CAT and GR activities detected in the roots were increased in plants grown at higher N. The increase in activity and number of bands of GR at high N in the roots of all three plants studied was not accompanied by a change in activity or the number of SOD isoforms. The possibility that the application of high N promotes the formation of reactive oxygen species by stimulating an increased rate of growth is discussed.