Chickpea seed endophyte Enterobacter sp. mediated yield and nutritional enrichment of chickpea for improving human and livestock health.

Chickpeas (Cicer arietinum L.) are used as a good source of proteins and energy in the diets of various organisms including humans and animals. Chickpea straws can serve as an alternative option for forage for different ruminants. This research mainly focussed on screening the effects of adding beneficial chickpea seed endophytes on increasing the nutritional properties of the different edible parts of chickpea plants. Two efficient chickpea seed endophytes (Enterobacter sp. strain BHUJPCS-2 and BHUJPCS-8) were selected and applied to the chickpea seeds before sowing in the experiment conducted on clay pots. Chickpea seeds treated with both endophytes showed improved plant growth and biomass accumulation. Notably, improvements in the uptake of mineral nutrients were found in the foliage, pericarp, and seed of the chickpea plants. Additionally, nutritional properties such as total phenolics (0.47, 0.25, and 0.55 folds), total protein (0.04, 0.21, and 0.18 folds), carbohydrate content (0.31, 0.32, and 0.31 folds), and total flavonoid content (0.45, 027, and 0.8 folds) were increased in different parts (foliage, pericarp, and seed) of the chickpea plants compared to the control plants. The seed endophyte-treated plants showed a significant increase in mineral accumulation and improvement in nutrition in the different edible parts of chickpea plants. The results showed that the seed endophyte-mediated increase in dietary and nutrient value of the different parts (pericarp, foliage, and seeds) of chickpea are consumed by humans, whereas the other parts (pericarp and foliage) are used as alternative options for forage and chaff in livestock diets and may have direct effects on their nutritional conditions.

Impact of bacterial volatiles on the plant growth attributes and defense mechanism of rice seedling.

Rice is a major dietary element for about two billion people worldwide and it faces numerous biotic and abiotic stress for its cultivation. Rice blast disease caused by Magnaporthe oryzae reduce up to 30 % rice yield. Overuse of synthetic chemicals raises concerns about health and environment; so, there is an urgent need to explore innovative sustainable strategies for crop productivity. The main aim of this study is to explore the impact of bacterial volatiles (BVCs) on seedling growth and defense mechanisms of rice under in-vitro condition. On the basis of plant growth promoting properties, six bacterial strains were selected out of ninety-one isolated strains for this study; Pantoea dispersa BHUJPVR01, Enterobacter cloacae BHUJPVR02, Enterobacter sp. BHUJPVR12, Priestia aryabhattai BHUJPVR13, Pseudomonas sp. BHUJPVWRO5 and Staphylococcus sp. BHUJPVWLE7. Through the emission of bacterial volatiles compounds (BVCs), Enterobacter sp., P. dispersa and P. aryabhattai significantly reduces the growth of rice blast fungus Magnaporthe oryzae by 69.20 %, 66.15 % and 62.31 % respectively. Treatment of rice seedlings with BVCs exhibited significant enhancement in defence enzyme levels, including guaiacol peroxidase, polyphenol oxidase, total polyphenols, and total flavonoids by a maximum of up to 24 %, 48 %, 116 % and 80 %, respectively. Furthermore, BVCs effectively promote shoot height, root height, and root counts of rice. All BVCs treated plant showed a significant increase in shoot height. P. dispersa treated plants showed the highest increase of 60 % shoot and 110 % root length, respectively. Root counts increased up to 30% in plants treated with E. cloacae and Staphylococcus sp. The BVCs can be used as a sustainable approach for enhancing plant growth attributes, productivity and defence mechanism of rice plant under biotic and abiotic stresses.

Harnessing of phytomicrobiome for developing potential biostimulant consortium for enhancing the productivity of chickpea and soil health under sustainable agriculture.

The main aim of the present work was to explore culturable bacteria and to develop potential microbial consortium as bio-inoculants for enhancing plant productivity, nutritional content, and soil health. For this study, we selected two bacterial strains e.g., Enterobacter hormaechei (BHUJPCS-15) and Brevundimonas naejangsanensis (BHUJPVCRS-1) based on plant growth-promoting activities We developed a consortium of both strains and estimated plant growth promotion (PGP) activity which recorded significant better production of Indole-3-acetic acid (IAA) (61.53 µg/ml), siderophore (12.66%), ammonia (98.66 µg/ml), phosphate solubilisation (942.64 µg/ml), potassium solubilisation, and antagonistic activity against Fusarium sp. than individual bacterial strains. Bacterial consortium (E. hormaechei + B. naejangsanensis) treatment significantly enhanced plant growth attributes, grain yields, nutritional content in plant and seed, followed by E. hormaechei as compared to control. Seed treated with consortium recorded a significant increase in available N P K, enzymes and microbial communities in soils. Microbiome analysis revealed that the dominance of bacterial group and its functional properties is directly correlated with plant growth attributes, nutrient content, soil N P K, and enzyme activity. The relative abundance of bacterial phyla Proteobacteria (98%) was dominantly recorded in all treatments. The microbiome of seed and soil, treated with consortium (E. hormaechei + B. naejangsanensis) showed high amount of diversity of bacterial phyla Verrucomicrobia, Firmicutes, Bacteroidetes, Acidobacteria, Chloroflexi, and Proteobacteria than E. hormaechei (Firmicutes, Bacteroidetes, Chloroflexi and Proteobacteria) and control (Firmicutes, Bacteroidetes and Proteobacteria). In soil, root and shoot, E. hormaechei treatment enriched ligninolytic, nitrogen fixation, cellulolytic, nitrate ammonification among other pathways. The main finding is that the consortium treated seed of chickpea recorded significant enhancement of plant growth attributes, productivity, nutritional content, and soil health as well as microbial colonization in soil and seed part.

Re-vitalizing of endophytic microbes for soil health management and plant protection.

Soil health management and increase crop productivity are challenging issues for researchers and scientists. Many research publications have given multiple technological solutions for improving soil health and crop productivity but main problem is sustainability of those technologies under field condition and different agro-climatic zone. Due to the random industrialization, deforestation, mining and other environmental factor reduce soil fertility and human health. Many alternative options e.g., crop rotation, green manuring, integrated farming, biofertilizer (plant-growth-promoting microorganism, microbial consortium of rhizosphere soils), and vermicomposting are available for adapting and improving the soil heath and crop productivity by farmers. Recent trends of new research dimension for sustainable agriculture, endophytic microbes and its consortium is one of the better alternative for increasing crop productivity, soil health and fertility management. However, current trends are focuses on the endophytic microbes, which are present mostly in all plant species. Endophytic microbes are isolated from plant parts-root, shoot, leaf, flower and seeds which have very potential ability of plant growth promotion and bio-controlling agent for enhancing plant growth and development. Mostly plant endophytes showed multi-dimensional (synergistic, mutualistic, symbiotic etc.) interactions within the host plants. It promotes the plant growth, protects from pathogen, and induces resistance against biotic and abiotic environmental stresses, and improves the soil fertility. Till date, most of the scientific research has been done on assuming that interaction of plant endophytes with the host is similar like the plant-growth-promoting microorganism (PGPM). It would be very interesting to explore the functional properties of plant endophytes to modulate the essential gene expression during biotic and abiotic stresses. Endophytes have the ability to induce the soil fertility by improving soil essential nutrient, enzymatic activity and influence the other physiochemical property. In this study, we have discussed details about functional properties of plant endophytes and their mechanism for enhancing plant productivity and soil health and fertility management under climate-resilient agricultural practices. Our main objective is to promote and explore the beneficial plant endophytes for enhancing sustainable agricultural productivity.

Phytomicrobiome for promoting sustainable agriculture and food security: Opportunities, challenges, and solutions.

Ensuring food security in an environmentally sustainable way is a global challenge. To achieve this agriculture productivity requires increasing by 70 % under increasingly harsh climatic conditions without further damaging the environmental quality (e.g. reduced use of agrochemicals). Most governmental and inter-governmental agencies have highlighted the need for alternative approaches that harness natural resource to address this. Use of beneficial phytomicrobiome, (i.e. microbes intimately associated with plant tissues) is considered as one of the viable solutions to meet the twin challenges of food security and environmental sustainability. A diverse number of important microbes are found in various parts of the plant, i.e. root, shoot, leaf, seed, and flower, which play significant roles in plant health, development and productivity, and could contribute directly to improving the quality and quantity of food production. The phytomicrobiome can also increase productivity via increased resource use efficiency and resilience to biotic and abiotic stresses. In this article, we explore the role of phytomicrobiome in plant health and how functional properties of microbiome can be harnessed to increase agricultural productivity in environmental-friendly approaches. However, significant technical and translation challenges remain such as inconsistency in efficacy of microbial products in field conditions and a lack of tools to manipulate microbiome in situ. We propose pathways that require a system-based approach to realize the potential to phytomicrobiome in contributing towards food security. We suggest if these technical and translation constraints could be systematically addressed, phytomicrobiome can significantly contribute towards the sustainable increase in agriculture productivity and food security.

Yeast a potential bio-agent: future for plant growth and postharvest disease management for sustainable agriculture.

The native microbial flora and fauna are replaced by commercial chemical fertilizers and pesticides, in the current agricultural system. Imbalance of beneficial microbial diversity and natural competitors increases the severity of plant diseases. Hence, sustainable agricultural practices like bio-inoculant, stress tolerant consortium, crop rotation and mix cropping sequences is only the solution of recharging the microbial population in soils to make healthier for crop productivity and suppression of soil borne phytopathogen. Microorganisms use several direct mechanism activities, e.g. production of plant hormones (indole-3-acetic acid), ammonium, siderophore and nutrient solubilization, and indirect mechanism activities, e.g. hydrogen cyanide, chitinase, protease and antibiotic for plant growth promotion. The plant growth-promoting effect of bacteria, fungi, mycorrhizal fungi and algae is widely explored. Yeast is a single-celled microbe classified as members of the kingdom fungi. Yeast and their product use in the food industry, medical science and biotechnological research purpose but very few literatures reported that yeasts have the ability to produce a group of plant growth-promoting activities and biocontrolling activity. Therefore, the main aim of this mini review is to highlight the application of yeasts as biological agents in different sectors of sustainable farming practices.