A novel R3H protein, OsDIP1, confers ABA-mediated adaptation to drought and salinity stress in rice

Abscisic acid (ABA) is a key component of many signaling networks mediating plant adaptation to various stresses. In this context, ABA-induced antioxidant defence is considered to be a main mechanism to that enhances water stress tolerance in plants. The specific details of this activation remain, however, elusive. In this work, we show that DIP1, a protein from novel R3H family, played a central role in modulating water stress tolerance in rice. OsDIP1 transcripts were induced by hydrogen peroxide (H2O2), ABA, drought (polyethylene glycol treatment), and salt stress. Overexpression of OsDIP1 in rice enhanced drought and salinity tolerance while knocking out OsDIP1 by CRISPR-Cas9 editing resulted in drought and salt sensitive phenotype. The activity and gene expression of antioxidant defence enzymes, superoxide dismutase (SOD), catalase (CAT), increased in OsDIP1-overexpressed transgenic rice plants, while the content of malondialdehyde (MDA) decreased. In contrast, the content and gene expression of SOD and CAT, decreased, and the content of MDA increased in knockout of OsDIP1 rice plants, suggesting that overexpression of OsDIP1 enhances the antioxidant capacity of rice plants. The yeast two hybrid screening test revealed that OsDIP1 interacted with ZFP36, a key zinc finger transcription factor involved in ABA-induced antioxidant defence. Moreover, OsDIP1 could modulate some key ABA-responsive genes via interacting with ZFP36. Overall, our findings indicate an important role of OsDIP1 in ABA-induced antioxidant defence signaling and adaptation to salinity and drought in rice.

Impact of water deficit on the development and senescence of tomato roots grown under various soil textures of Shaanxi, China

Purpose Water scarcity is expected to extend to more regions of the world and represents an alarming threat to food security worldwide. Under such circumstances, water holding capacity is an important agronomic trait, which is primarily controlled by soil texture. Methods Our work examined three different soil textures from three cities of Shaanxi Province in China, i.e., silt-sandy loam from Yulin (north of Shaanxi), loam—clay loam from Yangling (middle and western part of Shaanxi), and clay loam-clay from Hanzhong soil (south of Shaanxi), at two moisture levels, i.e., field capacity of 70–75% (well-watered) and 50–55% (water deficit). Results The differences in soil particle sizes altered the soil physiochemical properties and soil enzymatic activities. Soil urease and ß-glucosidase activities were significantly higher in the Yangling soil under the well-watered treatment, while the differences were nonsignificant under the water deficit conditions. The leaf photosynthesis rate and total chlorophyll content were significantly higher in Hanzhong soil after 15 days of treatment; however, the overall highest plant length, root cortex diameter, and xylem element abundance were significantly higher in Yangling soil under the water deficit conditions. Furthermore, comparable differences were observed in antioxidant defence enzymes and endogenous hormones after every 15 days of treatments. The auxin, gibberellic acid and cytokinin concentrations in leaves and roots were comparably high in Yangling soil, while the abscisic acid concentrations were higher in Hanzhong soil under the water deficit conditions. Conclusions Our findings concluded that soil compaction has a significant role not only in root morphology, growth, and development but also in the soil physicochemical properties and nutrient cycle, which are useful for the growth and development of tomato plants.

Polyprenols as Promising Neuropharmacological Agents

The article presents information about the potential effectiveness of polyprenols as a means of neuropharmacology. To confirm the neuroprotective effect of polyprenols, their effectiveness was studied in the case of chronic exposure to carbendazim. In such conditions, chronic damage to nerve cells is developed through violating the homeostasis of neurospecific proteins (S-100, MBP) and trophic factors, as well as a sharp activation of lipid peroxidation processes. The administration of polyphenols (2 mg/kg once a day for 2 weeks) to laboratory animals under modelled conditions reduced the manifestations of neurointoxication and statistically significantly contributed to the reduction of oxidative stress and activation of antioxidant defence enzymes (glutathione-S-transferase).

Growth inhibition of the toxic cyanobacterium Cylindrospermopsis raciborskii by extremely low-frequency electromagnetic fields

This study investigates the effects of extremely low-frequency electromagnetic fields (ELF-EMFs) on the growth and antioxidant defence enzymes of the toxic cyanobacterium Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju. To determine resonance frequency of growth inhibition of C. raciborskii, cells were subjected to ELF square amplitude modulated waves (QAMW) with a range of frequencies (0.1, 0.3, 0.5, 0.7, 0.9 Hz) at single intensity of 100 V m–1 for 30 minutes. The results revealed that the highest growth inhibition of Cylindrospermopsis occurred upon exposure to 0.7 Hz QAMW for 30 min. ELF-EMF-exposed cultures exhibited a marked decrease in cell number, chlorophyll-a content and activity of antioxidant enzymes compared to control cultures, and this effect increased with the prolongation of exposure time. Moreover, ELF-EMF induced morphological changes in Cylindrospermopsis cells upon exposure to 0.7 Hz QAMW for 120 min, including shrinking and disintegration of cytoplasmic contents, and thickening of the cell wall. Changes in dielectric properties, as a measure of interaction of cellular constituents (e.g., plasma membrane, cell wall and cytoplasm), with electromagnetic fields were also observed for treated cells. Our results provide a new possibility for using ELF-EMFs to eliminate toxic cyanobacteria from drinking and recreational water sources.

Effect of bacterial consortium on alfalfa (Medicago sativa L.) plant nutrient uptake and antioxidant enzymes at different levels of oily sludge

Under stress environment of oily sludge, plants develop oxidative stress which effect nutrients uptake, activity of oxidative defence enzymes, cause ion imbalance and toxicity in plants. The present study was designed to develop a combination of bacterial consortium alone and with fertilizers that can help to improve alfalfa growth and plant defence system under stress environment of oily sludge contamination soils. For this study consortium was prepared from Bacillus cereus (Acc KR232400), Bacillus altitudinis (Acc KF859970), Comamonas (Acc KF859971) and Stenotrophomonas maltophilia (Acc KF859973) and was inoculated with fertilizer to oily sludge contaminated soils. A pot experiment was conducted using complete randomized design with three replicates. The plants were harvested at 21 d for estimation of protein, proline and antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD). The protein, SOD and POD contents in alfalfa were higher in oily sludge than soil without consortium, ammonium nitrate and diamamoiun phosphate. Consortium suppressed the oxidative stress of sludge treated plants. The inoculation of bacterial consortium enhanced the uptake of Ca, Mg, K and Na. The uptake of Ca, Mg, K, Fe, Cu and Zn increased significantly with consortium+fertilizer the availability of nutrients in soil with 30% and 60% of oily. Cd content was greater in root than leaves of alfalfa. The bacterial consortium helped to enhance plant growth and plant anti-oxidant enzymes system. The consortium with fertilizer is the best suitable combination for alfalfa that can improve the oxidative enzyme system of alfalfa and increases its growth and development.

Green Synthesized Copper Oxide Nanoparticles Ameliorate Defence and Antioxidant Enzymes in Lens culinaris

Biosynthesis of copper oxide nanoparticles (CuONPs) in a cost-effective and eco-friendly way has gained its importance. CuONPs has been prepared from copper sulfate by using Adiantum lunulatum whole plant extract. CuONPs have been characterized by X-ray diffraction, Fourier transform infrared spectroscopic, transmission electron microscope, etc. Mono-disperse, spherical, pure, and highly stable CuONPs have formed with an average diameter of 6.5 ± 1.5 nm. Biosynthesized CuONPs at different concentrations were applied to seeds of Lens culinaris. Physiological characteristics were investigated in the germinated seeds. Roots obtained from the seeds treated with 0.025 mgmL−1 concentration of CuONPs showed highest activity of different defence enzymes and total phenolics. However, at higher concentration it becomes close to control. It showed gradual increase of antioxidative enzymes, in accordance with the increasing dose of CuONPs. Likewise, lipid peroxidation and proline content gradually increased with the increasing concentration. Reactive oxygen species and nitric oxide generation was also altered due to CuONPs treatment indicating stress signal transduction. Finally, this study provides a new approach of the production of valuable CuONPs, is a unique, economical, and handy tool for large scale saleable production which can also be used as a potent plant defence booster instead of other commercial uses.

A viral ring nuclease anti-CRISPR subverts type III CRISPR immunity

ABSTRACTThe CRISPR system provides adaptive immunity against mobile genetic elements in bacteria and archaea. On detection of viral RNA, type III CRISPR systems generate a cyclic oligoadenylate (cOA) second messenger1–3, activating defence enzymes and sculpting a powerful antiviral response that can drive viruses to extinction4,5. Cyclic nucleotides are increasingly implicated as playing an important role in host-pathogen interactions6,7. Here, we identify a widespread new family of viral anti-CRISPR (Acr) enzymes that rapidly degrade cyclic tetra-adenylate (cA4). The viral ring nuclease (AcrIII-1) is the first Acr described for type III CRISPR systems and is widely distributed in archaeal and bacterial viruses, and proviruses. The enzyme uses a novel fold to bind cA4specifically and utilizes a conserved active site to rapidly cleave the signalling molecule, allowing viruses to neutralise the type III CRISPR defence system. The AcrIII-1 family has a broad host range as it targets cA4signalling molecules rather than specific CRISPR effector proteins. This study highlights the crucial role of cyclic nucleotide signalling in the conflict between viruses and their hosts.

Analysis of biochemical changes in cultivars of Black gram, Green gram and Pea against powdery mildew

Powdery mildew disease of the Black gram, Mung bean and Pea are a major constraint in the production. The resistance of plants to various pathogens depends on synthesis and level of various defence enzymes like hydrolases; peroxidases and antimicrobial compounds like phytoalexins (Kuc, l991 et al Kauffmann et al. l987; Boiler, l987; Mauch et al., l988; Kale and Choudhary 200l, Koche and Choudhary, 2005). The present study focused on visual screening of selected crop cultivars against the powdery mildew and its biochemical correlation with chlorophyll content, sugars, phenols content, PR-proteins and Phytoalexin activities. From the field studies, it was observed that selected crop was found with powdery mildew incidence. This disease incidence data was correlated with biochemical changes and level of chlorophyll, sugars, phenols, PR-protein and Phytoalexin activities.