Accumulation of resveratrol, ferulic acid and iron in seeds confer iron deficiency chlorosis tolerance to a novel genetic stock of peanut (Arachis hypogaea L.) grown in calcareous soils.

Peanut is mostly grown in calcareous soils with high pH which are deficient in available iron (Fe2+) for plant uptake causing iron deficiency chlorosis (IDC). The most pertinent solution is to identify efficient genotypes showing tolerance to limited Fe availability in the soil. A field screening of 40 advanced breeding lines of peanut using NRCG 7472 and ICGV 86031 as IDC susceptible and tolerant checks, respectively, was envisaged for four years. PBS 22040 and 29,192 exhibited maximum tolerance while PBS 12215 and 12,185 were most susceptible. PBS 22040 accumulated maximum seed resveratrol (5.8 ± 0.08 ppm), ferulic acid (378.6 ± 0.31 ppm) and Fe (45.59 ± 0.41 ppm) content. Enhanced chlorophyll retention (8.72-9.50 µg ml-1), carotenoid accumulation (1.96-2.08 µg ml-1), and antioxidant enzyme activity (APX: 35.9-103.9%; POX: 51- 145%) reduced the MDA accumulation (5.61-9.11 µM cm-1) in tolerant lines. The overexpression of Fe transporters IRT1, ZIP5, YSL3 was recorded to the tune of 2.3-9.54; 1.45-3.7; 2.20-2.32- folds respectively in PBS 22040 and 29,192, over NRCG 7472. PBS 22040 recorded the maximum pod yield (282 ± 4.6 g/row), hundred kernel weight (55 ± 0.7 g) and number of pods per three plants (54 ± 1.7). The study thus reports new insights into the roles of resveratrol, ferulic acid and differential antioxidant enzyme activities in imparting IDC tolerance. PBS 22040, being the best performing line, can be the potent source of IDC tolerance for introgression in high yielding but susceptible genotypes under similar edaphic conditions. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01321-9.

Alleviation of Salinity Stress in Peanut by Application of Endophytic Bacteria.

The development of salinity affects 7% of the world's land surface, acting as a major constraint to crop productivity. This study attempted to use the co-evolving endophytes of peanut to alleviate salinity stress and enhance the yield of peanut. Diverse and different tissue colonizing endophytes were isolated from peanut and screened in vitro by seed germination bioassay imposing gradients of salinity, with two cultivars TG37A (susceptible) and GG2 (moderately resistant), in potted conditions using saline irrigation water. Finally, nine endophytes capable of producing IAA and ACC-deaminase, promoting root growth and yield in potted conditions were selected for further evaluation in field conditions. They were evaluated with saline water (1.5-2.0 dS/m) in saline soil with susceptible cultivar TG37A. Simultaneously, three endophytes (Bacillus firmus J22N; Bacillus tequilensis SEN15N; and Bacillus sp. REN51N) were evaluated with two cultivars, GG2 and TG37A, during rainy and post-rainy seasons with elevated salinity. The application of endophytes like Bacillus firmus J22N and Bacillus sp. REN51N enhanced the pod and haulm yield of peanuts by 14-19% across cultivars, salinity, and seasons. In addition, there was significant modulation in parameters like relative water content; production of enzymes like superoxide dismutase (SOD), glutathione reductase (GR), catalase (CAT), ascorbate peroxidase (APX), lipid peroxidase (POD), and H2O2 content in leaf; and uptake of potassium. The activities of the enzymes involved in scavenging reactive oxygen species (ROS) increased with salinity, and further increased with endophytes like Bacillus firmus J22N, Bacillus tequilensis SEN15N, and Bacillus sp. REN51N. There was an enhanced accumulation of proline, reduced level of phenol and H2O2, and enhanced uptake of potassium with the inoculation of endophytes. This improved scavenging capacity of plants by endophytic modulation of ROS scavengers, uptake of K, production of ACC deaminase and IAA, root and biomass growth, modulation in relative water content, and enhanced accumulation of osmoprotectant might be the reasons of alleviation of salinity stress. Endophytes could have alleviated salinity stress in peanuts, indicating the mechanisms and potential of peanuts at the field level. These endophytes could be applied to bring agricultural sustainability to salinity-affected areas in the future. Furthermore, few genera viz. Kocuria, Brevundimonas, Agrococcus, Dietzia, and Kytococcus were observed in peanut tissue for the first time.

Haloarchaea Endowed with Phosphorus Solubilization Attribute Implicated in Phosphorus Cycle.

Archaea are unique microorganisms that are present in ecological niches of high temperature, pH and salinity. A total of 157 archaea were obtained from thirteen sediment, water and rhizospheric soil samples collected from Rann of Kutch, Gujarat, India. With an aim to screen phosphate solubilizing archaea, a new medium was designed as Haloarchaea P Solubilization (HPS) medium. The medium supported the growth and P solubilization activity of archaea. Employing the HPS medium, twenty isolates showed the P-solubilization. Phosphate solubilizing archaea were identified as seventeen distinct species of eleven genera namely Haloarcula, Halobacterium, Halococcus, Haloferax, Halolamina, Halosarcina, Halostagnicola, Haloterrigena, Natrialba, Natrinema and Natronoarchaeum. Natrinema sp. strain IARI-WRAB2 was identified as the most efficient P-solubilizer (134.61 mg/L) followed by Halococcus hamelinensis strain IARI-SNS2 (112.56 mg/L). HPLC analysis detected seven different kinds of organic acids, namely: gluconic acid, citric acid, formic acid, fumaric acid succinic acid, propionic acid and tartaric acid from the cultures of these isolates. These phosphate solubilizing halophilic archaea may play a role in P nutrition to vegetation growing in these hypersaline soils. This is the first report for these haloarchaea to solubilize considerable amount of P by production of organic acids and lowering of pH.

Draft Genome Sequence of an Extreme Haloarchaeon 3A1-DGR Isolated from a Saltern Crystallizer of the Little Rann of Kutch, India.

Haloarchaea are predominant in the salt crystallizers of the Rann of Kutch when the concentration of salts approaches saturation levels. The obligate and extreme halophilic archaeon 3A1-DGR, isolated from a salt crystallizer pond of the Little Rann of Kutch, India, needs minimum of 10 % NaCl in the growth medium. To understand the mechanism(s) of osmotolerance and adaptation at extreme osmolarity, and to mine relevant gene(s), the genome of this haloarchaeon, 3A1-DGR, was sequenced. We report here, the 2.88 Mb draft genome sequence of the haloarchaeon 3A1-DGR, with G+C content of 68 % and the possible involvement of 43 genes in stress tolerance. Further studies of the genome of this haloarchaeon would be required to identify gene(s) that might be responsible for imparting extreme osmotolerance.

Insight into the First Draft Genome Sequence of the Genus Sediminibacillus, Sediminibacillus halophilus Strain NSP9.3.

We report the 3.98-Mbp first draft genome sequence of Sediminibacillus halophilus strain NSP9.3, a moderate halophile isolated from a seasonal salt marsh of the Great Rann of Kutch, India. Exploring the genome of this organism will facilitate the understanding of the mechanism(s) of osmotolerance and survival in differential osmolarity.

Draft Genome Sequence of a Moderately Halophilic Bacillus megaterium Strain, MSP20.1, Isolated from a Saltern of the Little Rann of Kutch, India.

The 4.37-Mbp draft genome of a moderately halophilic Bacillus megaterium strain, MSP20.1, isolated from a saltern of the Little Rann of Kutch, India, is reported here. To understand the mechanism(s) of moderate halophilism and to isolate the gene(s) involved in osmotolerance and adaptation, the genome of MSP20.1 was sequenced.

Draft Genome Sequence of the Obligate Halophilic Bacillus sp. Strain NSP22.2, Isolated from a Seasonal Salt Marsh of the Great Rann of Kutch, India.

Here, we report the 4.0-Mbp draft genome of an obligate halophile, Bacillus sp. strain NSP22.2, isolated from a seasonal salt marsh of the Great Rann of Kutch, India. To understand the mechanism(s) of obligate halophilism and to isolate the relevant gene(s), the genome of Bacillus sp. NSP22.2 was sequenced.

Draft Genome Sequence of an Obligate and Moderately Halophilic Bacterium, Thalassobacillus devorans Strain MSP14, the First Draft Genome of the Genus Thalassobacillus.

We report the 3.93-Mbp first draft genome sequence of a species of the genus Thalassobacillus, Thalassobacillus devorans strain MSP14, a moderate but obligate halophile, isolated from a salt crystallizer of the Little Rann of Kutch, India. Exploring the genome of this organism will facilitate understanding the mechanism(s) of its obligate halophilism.

Draft Genome Sequence of Bacillus sp. Strain SB47, an Obligate Extreme Halophile Isolated from a Salt Pan of the Little Rann of Kutch, India.

Here, we report the 4.46-Mbp draft genome sequence of Bacillus sp. strain SB47, an extreme halophile isolated from a salt pan of the Little Rann of Kutch, India. Exploring the genome of this organism will facilitate the understanding and isolation of the gene(s) involved in its extreme osmotolerance.

Draft Genome Sequence of Bacillus sp. Strain NSP9.1, a Moderately Halophilic Bacterium Isolated from the Salt Marsh of the Great Rann of Kutch, India.

We report the 4.52-Mbp draft genome sequence of Bacillus sp. strain NSP9.1, a moderately halophilic bacterium isolated from the salt marsh of the Great Rann of Kutch, India. Analysis of the genome of this organism will lead to a better understanding of the genes and metabolic pathways involved in imparting osmotolerance.

Draft Genome Sequence of the Extremely Halophilic Bacillus sp. Strain SB49, Isolated from a Salt Crystallizer Pond of the Little Rann of Kutch, India.

Here we report the draft whole-genome sequence (3.72 Mbp) of Bacillus sp. strain SB49, an extremely halophilic bacterium isolated from a salt crystallizer pond of the Little Rann of Kutch in India. Unraveling the genome of this organism will facilitate understanding and isolation of the genes involved in imparting extreme osmotolerance.

Draft Genome Sequence of Bacillus sp. Strain NSP2.1, a Nonhalophilic Bacterium Isolated from the Salt Marsh of the Great Rann of Kutch, India.

The 5.52-Mbp draft genome sequence of Bacillus sp. strain NSP2.1, a nonhalophilic bacterium isolated from the salt marsh of the Great Rann of Kutch, India, is reported here. An analysis of the genome of this organism will facilitate the understanding of its survival in the salt marsh.

Draft Genome Sequence of Salinibacillus aidingensis Strain MSP4, an Obligate Halophilic Bacterium Isolated from a Salt Crystallizer of the Rann of Kutch, India.

We report the 7.42-Mbp draft whole genome sequence of Salinibacillus aidingensis strain MSP4, an obligate halophilic bacterium, isolated from a salt crystallizer of the Rann of Kutch in India. Analysis of the genome of this organism will lead to a better understanding of the genes and metabolic pathways involved in imparting osmotolerance.