Antioxidant activity of winter wheat when treated with the biopreparation Nigor++

The influence of stress factors on the plant can lead to deterioration of plant functioning and loss of yield. The use of biological preparations based on plant cell elicitors in the technology of grain cultivation makes it possible to regulate the antioxidant activity of plants under abiotic stress. Treatment with the biopreparation Nigor++ in the tillering phase leads to noticeable changes in the balance of antioxidant substances in winter wheat plants Moskovskaya 39. Repeated treatment of Nigor++ after 16 days in the earing phase reduces AOA by 21.8, and by the flowering phase leads to a drop in this indicator by 51% relative to the tillering phase and by 59% relative to control plants. The use of Nigor++ increases the immune status of plants, reduces the concentration of antioxidant substances or reduces their activity due to the formation of stable complexes with magnesium ions included in BP, as well as binding them to highly active free radicals that occur during autoxidation, converting them to low-activity. Keywords: ANTIOXIDANTS, BIOLOGICAL PRODUCTS, WINTER WHEAT, ANTIOXIDANT ACTIVITY, REACTIVE OXYGEN SPECIES, ELICITORS, BIOFLAVONOIDS

Physiological and Transcriptional Responses of Industrial Rapeseed (Brassica napus) Seedlings to Drought and Salinity Stress

Abiotic stress greatly inhibits crop growth and reduces yields. However, little is known about the transcriptomic changes that occur in the industrial oilseed crop, rapeseed (Brassica napus), in response to abiotic stress. In this study, we examined the physiological and transcriptional responses of rapeseed to drought (simulated by treatment with 15% (w/v) polyethylene glycol (PEG) 6000) and salinity (150 mM NaCl) stress. Proline contents in young seedlings greatly increased under both conditions after 3 h of treatment, whereas the levels of antioxidant enzymes remained unchanged. We assembled transcripts from the leaves and roots of rapeseed and performed BLASTN searches against the rapeseed genome database for the first time. Gene ontology analysis indicated that DEGs involved in catalytic activity, metabolic process, and response to stimulus were highly enriched. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that differentially expressed genes (DEGs) from the categories metabolic pathways and biosynthesis of secondary metabolites were highly enriched. We determined that myeloblastosis (MYB), NAM/ATAF1-2/CUC2 (NAC), and APETALA2/ethylene-responsive element binding proteins (AP2-EREBP) transcription factors function as major switches that control downstream gene expression and that proline plays a role under short-term abiotic stress treatment due to increased expression of synthesis and decreased expression of degradation. Furthermore, many common genes function in the response to both types of stress in this rapeseed.

Ipomoea pes-caprae IpASR Improves Salinity and Drought Tolerance in Transgenic Escherichia coli and Arabidopsis

Ipomoea pes-caprae L. is an extremophile halophyte with strong adaptability to seawater and drought. It is widely used in the ecological restoration of coastal areas or degraded islands in tropical and subtropical regions. In this study, a new abscisic acid, stressandripening (ASR) gene, IpASR, was reported, and is mainly associated with biological functions involved in salt and drought tolerance. Sequence analysis of IpASR showed that this protein contains an ABA/WDS (abscisic acid/water deficit stress) domain, which is a common feature of all plant ASR members. Overexpression of IpASR improved Escherichia coli growth performance compared with the control under abiotic stress treatment. The transgenic overexpressing IpASR Arabidopsis showed higher tolerance to salt and drought stress than the wild type and lower accumulation of hydrogen peroxide (H2O2) and superoxide (O2−) accompanied by increased antioxidant enzyme activity in vivo. IpASR exhibits transcription factor’s activity. Therefore, the overexpression of IpASR in Arabidopsis is supposed to influence the expression of some genes involved in anti-oxidative and abiotic stresses. The results indicate that IpASR is involved in the plant response to salt and drought and probably acts as a reactive oxygen species scavenger or transcription factor, and therefore influences physiological processes associated with various abiotic stresses in plants.

Expression study of soybean germin-like gene family reveals a role of GLP7 gene in various abiotic stress tolerances

Germin-like proteins (GLPs) are ubiquitous plant glycoproteins (belonging to the cupin super family) that play diverse roles, including abiotic stress resistance in many plant species. To identify the molecular functions underlying abiotic stress responses, the expression of germin-like protein encoding genes of soybean GmGLPs was analyzed. qRT-PCR analyses of 21 GmGLPs transcripts abundances were conducted in soybean leave tissues. The results showed that GmGLPs transcripts were highly abundant upon treatments with high salinity, PEG6000, abscisic acid (ABA) and methyl viologen (MV). The peaks of transcript copiousness induced by PEG6000 and NaCl were mostly observed after 18 h, while some genes expressed earlier than 4 h after abiotic stress treatment. A specific GmGLP7 gene, that was highly abundant under salinity, drought, ABA and MV conditions, was further characterized. The ectopic overexpression of GmGLP7 (Glyma.08G226800.1) in transgenic Arabidopsis enhanced drought, salt, and oxidative tolerance and resulted in hypersensitive phenotypes toward ABA-mediated seed germination and primary root elongation, compared to the wild-type. Taken together, these results suggest that GmGLP7 positively confers abiotic tolerance in plants.