EFFECT OF SALT (NACL) STRESS ON GERMINATION AND EARLY SEEDLING GROWTH OF FOUR VEGETABLES SPECIES

Due to increasing salinity problems, in this experiment four vegetables species were treated with different concentration of salt solution to study salt effect. Results indicated that salinity caused signifi cant reduction in germination percentage, germination rate, root and shoot lengths and fresh root and shoot weights. Liner relation was developed to fi nd relation between salt stress and plant growth and also between germination and rest of plant characters

Crescimento reduzido por salinidade, fotoquímica PS2 e conteúdo de clorofila em rabanete

When plants are grown under saline conditions, photosynthetic activity decreases leading to reduced plant growth, leaf area, chlorophyll content and chlorophyll fluorescence. Seeds and seedlings of radish (Raphanus sativus L.) were grown in NaCl solutions under controlled greenhouse conditions. The NaCl concentrations in complete nutrient solutions were 0 (control), 4.7, 9.4 and 14.1 dS m-1. The salinity reduced germination percentage and also delayed the germination rate as the salt level increased. Lengths and fresh weights of root and shoot decreased with the increasing salt concentration. Furthermore, photochemical efficiency of PS2 (Fv/Fm), photochemical quenching coefficient (qP), non photochemical quenching coefficient (qN), leaf area and chlorophyll content (SPAD value) were also reduced (P < 0.001) by salt stress. In contrast, the Fo/Fm ratio increased with increasing salt concentration while salinity showed no effect on the efficiency of excitation captured by open PS2 (Fv'/Fm'), electron transport rate (ETR), and leaf water content. Linear regression shows that the photochemical efficiency of PS2 (Fv/Fm) had a positive relationship with the photochemical quenching coefficient (qP), leaf area and chlorophyll content but had no relation with Fv'/Fm', Fo/Fm, and qN.Quando plantas crescem sob condições de salinidade, sua atividade fotossintética diminui levando a um crescimento reduzido, menor área foliar, conteúdo de clorofila e fluorescência de clorofila. Sementes e plântulas de rabanete (Raphanus sativus L.) foram germinadas e conduzidas em soluções de NaCl sob condições controladas de casa de vegetação. As concentrações de NaCl adicionado a solução nutritiva completa foram 0 (Controle), 4,7; 9,4 e 14,1 dS m-1. A salinidade diminui a percentagem de germinação e também atrasou a taxa de germinação com o aumento do nível de sal. Comprimento e peso fresco da parte aérea e da raiz decresceram com o aumento da concentração salina. Além disso, a eficiência fotoquímica de PS2 (Fv/Fm), o coeficiente fotoquímico de 'quenchin" (q p), o coeficiente não fotoquímico de "quenching" (q n), a área foliar e o teor de clorofila (valor SPAD) também foram reduzidos (P < 0,001) por estresse de sal. Ao contrário, a relação Fo/Fm aumentou com a concentração salina, ao passo que a salinidade não teve efeito sobre a eficiência de excitação capturada pelo PS2 aberto (Fv'/Fm'), taxa de transporte eletrônico (ETR) e conteúdo de água na folha. Através de regressão linear mostrou-se que a eficiência fotossintética de PS2 (Fv/Fm) teve uma relação positiva com o coeficiente fotoquímico de "quenching" (q p), área foliar e conteúdo de clorofila, mas nenhuma relação com (Fv/Fm), (Fo/Fm), e q n

Effect of soil salinity on the growth, amino acids and ion contents of rice transgenic lines

Rice seedling of different transgenic lines (T-99, T-112, T-115 and T-121) were grown in sand culture with salt concentration of 0, 50, 100 and 150 mM to determine the effect of salinity on growth, amino acid, and ion contents. It was observed that all the lines could tolerate concentration of up to 50 mM of salt solution. The lines (T-99, T-112 and T-115) were more salt tolerant even at a concentration of 100 mM of NaCl with their relative growth rate (RGR), and net assimilation rate (NAR) were unaffected as compared to the control. With the increase in salt concentrations, the proline contents increased for all the transgenic lines. On the other hand, a gradual decrease in the contents of glycine and arginine were observed with the increase in salinity treatments. A massive increase in the Na+ contents was measured in all the transgenic lines by application of the saline solutions. The K+ and Ca++ contents decreased with the increase in salt concentrations. The present study shows that although the plants accumulated Na, the lines T-99, T-112 and T-115 could tolerate concentrations of up to 100 mM.Key words: Salt stress, proline, glycine, Na, K, Ca, Oryza sativa

Bacillus subtilis Synthesized Iron Oxide Nanoparticles (Fe3O4 NPs) Induced Metabolic and Anti-Oxidative Response in Rice (Oryza sativa L.) under Arsenic Stress

Nanoparticle (NP) application is most effective in decreasing metalloid toxicity. The current study aimed to evaluate the effect of Bacillus subtiles synthesized iron oxide nanoparticles (Fe3O4 NPs) against arsenic (As) stress on rice (Oryza sativa L.) seedlings. Different concentrations of As (5, 10 and 15 ppm) and Bacillus subtilis synthesized Fe3O4 NPs solution (5, 10 and 15 ppm) alone and in combination were applied to rice seedlings. The results showed that As at 15 ppm significantly decreased the growth of rice, which was increased by the low level of As. Results indicated that B. subtilis synthesized Fe3O4 NP-treated plants showed maximum chlorophyll land protein content as compared with arsenic treatment alone. The antioxidant enzymes such as SOD, POD, CAT, MDA and APX and stress modulators (Glycine betain and proline) also showed decreased content in plants as compared with As stress. Subsequently, Bacillus subtilis synthesized Fe3O4 NPs reduced the stress associated parameters due to limited passage of arsenic inside the plant. Furthermore, reduction in H2O2 and MDA content confirmed that the addition of Bacillus subtilis synthesized Fe3O4 NPs under As stress protected rice seedlings against arsenic toxicity, hence enhanced growth was notice and it had beneficial effects on the plant. Results highlighted that Fe3O4 NPs protect rice seedlings against arsenic stress by reducing As accumulation, act as a nano adsorbent and restricting arsenic uptake in rice plants. Hence, our study confirms the significance of Bacillus subtilis synthesized Fe3O4 NPs in alleviating As toxicity in rice plants

Biosynthesized Iron Oxide Nanoparticles (Fe3O4 NPs) Mitigate Arsenic Toxicity in Rice Seedlings

Arsenic (As) contamination has emerged as a serious public health concern worldwide because of its accumulation and mobility through the food chain. Therefore, the current study was planned to check the effect of Bacillus subtilis-synthesized iron oxide nano particles (Fe3O4 NP) on rice (Oryza Sativa L.) growth against arsenic stress (0, 5, 10 and 15 ppm). Iron oxide nanoparticles were extracellular synthesized from Bacillus subtilis with a desired shape and size. The formations of nanoparticles were differentiated through UV-Visible Spectroscopy, FTIR, XRD and SEM. The UV-Visible spectroscopy of Bacillus subtilis-synthesized nanoparticles showed that the iron oxide surface plasmon band occurs at 268 nm. FTIR results revealed that different functional groups (aldehyde, alkene, alcohol and phenol) were present on the surface of nanoparticles. The SEM image showed that particles were spherical in shape with an average size of 67.28 nm. Arsenic toxicity was observed in seed germination and young seedling stage. The arsenic application significantly reduced seed germination (35%), root and shoots length (1.25 and 2.00 cm), shoot/root ratio (0.289), fresh root and shoots weight (0.205 and 0.260 g), dry root and shoots weight (6.55 and 6.75 g), dry matter percentage of shoot (12.67) and root (14.91) as compared to control. Bacillus subtilis-synthesized Fe3O4 NPs treatments (5 ppm) remarkably increased the germination (65%), root and shoot length (2 and 3.45 cm), shoot/root ratio (1.24) fresh root and shoot weight (0.335 and 0.275 mg), dry root and shoot weight (11.75 and 10.6 mg) and dry matter percentage of shoot (10.40) and root (18.37). Results revealed that the application of Fe3O4 NPs alleviated the arsenic stress and enhanced the plant growth. This study suggests that Bacillus subtilus-synthesized iron oxide nanoparticles can be used as nano-adsorbents in reducing arsenic toxicity in rice plants

Combine Effect of ZnO NPs and Bacteria on Protein and Gene’s Expression Profile of Rice (<i>Oryza sativa</i> L.) Plant

Heavy metal (HM) emissions have increased due to the impact of rising urbanization and anthropogenic activity, affecting different parts of the environment. The goal of this study is to investigate the combined effect of ZnO NPs and bacteria treatment on protein and gene expression profiles of rice plants that are grown in HMs-polluted water. Seeds were primed with Bacillus spp. (Bacillus cereus and Lysinibacillus macroides) before being cultured in Hoagland media containing ZnO NPs (5 and 10 mg/L) and HMs-contaminated water from the Hayatabad industrial estate (HIE), Peshawar, Pakistan. The results revealed that the maximum nitrogen and protein content was observed in the root, shoot, and leaf of the plant grown by combining bacteria-ZnO NPs treatment under HMs stress as compared with plant grown without or with individual treatments of ZnO NPs and bacteria. Furthermore, protein expression analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) revealed that plants that were grown in HMs-polluted water were found to be affected in contaminated water, however the combined effect of bacteria-ZnO NPs reported the more dense protein profile as compared with their individual treatments. Subsequently, plants that were grown in HMs-polluted water have the highest expression levels of stress-induced genes such as myeloblastosis (Myb), zinc-finger protein (Zat-12), and ascorbate peroxidase (Apx) while the combined effect revealed minimum expression as compared with individual treatments. It is concluded that the combined effect of ZnO NPs and bacteria lowered the stress-induced gene expression while it increased the nitrogen-protein content and protein expression in plant grown under HMs stress

Inhibitory Effects of Protopanaxadiol-Producing Transgenic Rice Seed Extracts on RANKL-Induced Osteoclast Differentiation

(1) Background: Osteoporosis is a disease in which bones are weakened and fractured easily because of various factors. It is mainly observed in elderly and postmenopausal women, and it continues to carry high economic costs in aging societies. Normal bone maintains a healthy state through a balanced process of osteoclast suppression and osteoblast activation; (2) Methods: In this study, osteoclast inhibition was induced by inhibiting osteoclast differentiation using ginseng protopanaxadiol-enriched rice (PPD-rice) seed extract. To analyze the effect of PPD-rice extract on the inhibition of osteoclast differentiation, bone marrow macrophages extracted from mice were treated with PPD-rice and Dongjin seed (non-transformed rice) extracts and analyzed for the inhibition of osteoclast differentiation; (3) Results: The results illustrated that PPD-rice extract reduced the transcription and translation of NFATc1, a modulator of osteoclast formation, decreased the mRNA expression of various osteoclast differentiation marker genes, and reduced osteoclast activity. Moreover, the bone resorptive activity of osteoclasts was diminished by PPD-rice extract on Osteo Assay plates; (4) Conclusions: Based on these results, PPD-rice extract is a useful candidate therapeutic agent for suppressing osteoclasts, an important component of osteoporosis, and it could be used as an ingredient in health supplements