Explore the vast range of titles available.

Climate change augments the risk to food security by inducing drought stress and a drastic decline in global rice production. Plant growth-promoting bacteria (PGPB) have been known to improve plant growth under drought stress. Here in the present study, we isolated, identified, and well-characterized eight drought-tolerant bacteria from the rice rhizosphere that are tolerant to 20% PEG-8000. These strains exhibited multiple plant growth-promoting traits, i.e., 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, exopolysaccharide production, phosphate (P)-solubilizing activity (51–356 µg ml -1 ), indole-3 acetic acid (IAA) production (14.3–46.2 µg ml -1 ), and production of organic acids (72–178 µg ml -1 ). Inoculation of bacterial consortium ( Bacillus subtilis NM-2, Brucella haematophilum NM-4, and Bacillus cereus NM-6) significantly improved seedling growth and vigor index (1009.2-1100) as compared to non-inoculated stressed plants (630-957). Through rhizoscanning, efficiency of the consortium was validated by improved root parameters such as root length (17%), diameter, and surface area (18%) of all tested genotypes as compared with respective non-inoculated stressed treatments. Furthermore, the response of consortium inoculation on three rice genotypes was positively correlated with improved plant growth and drought stress ameliorating traits by the accumulation of osmoprotectant, i.e., proline (85.8%–122%), relative water content (51%), membrane stability index (64%), and production of antioxidant enzymes to reduce oxidative damage by reactive oxygen species. A decrease in temperature and improved chlorophyll content of inoculated plants were found using infrared thermal imaging and soil plant analyzer development (SPAD), respectively. The key supporting role of inoculation toward stress responses was validated using robust techniques like infrared thermal imaging and an infrared gas analyzer. Furthermore, principal component analysis depicts the contribution of inoculation on stress responses and yield of tested rice genotypes under water stress. The integration of drought-tolerant rice genotype (NIBGE-DT02) and potential bacterial strains, i.e., NM-2, NM-4, and NM-6, can serve as an effective bioinoculant to cope with water scarcity under current alarming issues related to food security in fluctuating climate.

Soil CO2 concentration and flux measurements are important in diverse fields, including geoscience, climate science, soil ecology, and agriculture. However, practitioners in these fields face difficulties with existing soil CO2 gas probes, which have had problems with high costs and frequent failures when deployed. Confronted with a recent research project’s need for long-term in-soil CO2 monitoring at a large number of sites in harsh environmental conditions, we developed our own CO2 logging system to reduce expense and avoid the expected failures of commercial instruments. Our newly developed soil probes overcome the central challenge of soil gas probes—surviving continuous exposure to soil moisture while remaining open to soil gases—via three approaches: a 3D printed housing (economical for small-scale production) following design principles that correct the usual water permeability flaw of 3D printed materials; passive moisture protection via a hydrophobic, CO2-permeable PTFE membrane; and active moisture protection via a low-power micro-dehumidifier. Our CO2 instrumentation performed well and yielded a high-quality dataset that includes signals related to a prescribed fire as well as seasonal and diel cycles. We expect our technology to support underground CO2 monitoring in fields where it is already practiced and stimulate its expansion into diverse new fields.

Photosynthesis is a vital process for the planet. Its estimation involves the measurement of different variables and its processing through a mathematical model. This article presents a black-box mathematical model to estimate the net photosynthesis and its digital implementation. The model uses variables such as: leaf temperature, relative leaf humidity, and incident radiation. The model was elaborated with obtained data from Capsicum annuum L. plants and calibrated using genetic algorithms. The model was validated with Capsicum annuum L. and Capsicum chinense Jacq. plants, achieving average errors of 3% in Capsicum annuum L. and 18.4% in Capsicum chinense Jacq. The error in Capsicum chinense Jacq. was due to the different experimental conditions. According to evaluation, all correlation coefficients (Rho) are greater than 0.98, resulting from the comparison with the LI-COR Li-6800 equipment. The digital implementation consists of an FPGA for data acquisition and processing, as well as a Raspberry Pi for IoT and in situ interfaces; thus, generating a useful net photosynthesis device with non-invasive sensors. This proposal presents an innovative, portable, and low-scale way to estimate the photosynthetic process in vivo, in situ, and in vitro, using non-invasive techniques.

Maize is a low-temperature (LT)-sensitive plant and its physiological responses towards LT of temperate regions developed is an adaptive trait. To further our understanding about the response of maize to LT at the physiological and photosynthesis level, we conducted Infrared Gas Analysis (IRGA using LICOR6400-XT in 45-day-old grown two maize genotypes, one from temperate region (Gurez-Kashmir Himalayas), viz., Gurez local (Gz local), and another from tropics (Gujarat), viz., GM6. This study was carried out to evaluate the underlying physiological mechanisms in the two differentially temperature-tolerant maize genotypes. Net photosynthetic rate (A/PN), 18.253 in Gz local and 25.587 (µmol CO2 m−2 s−1) in GM6; leaf conductance (gs), 0.0102 in Gz local and 0.0566 (mmol H2O m−2 s−1) in GM6; transpiration rate (E), 0.5371 in Gz local and 2.9409 (mmol H2O m−2 s−1) in GM6; and water use efficiency (WUE), 33.9852 in Gz local and 8.7224 (µmol CO2 mmol H2O−1) in GM6, were recorded under ambient conditions. Also, photochemical efficiency of photosystem II (PSII) (Fv/Fm), 0.675 in Gz local and 0.705 in GM6; maximum photochemical efficiency (Fv′/Fm′), 0.310234 in Gz local and 0.401391 in GM6; photochemical quenching (qP), 0.2375 in Gz local and 0.2609 in GM6; non-photochemical quenching (NPQ), 2.0036 in Gz local and 1.1686 in GM6; effective yield of PSII (ФPSII), 0.0789 in Gz local and 0.099 in GM6; and electron transport rate (ETR), 55.3152 in Gz local and 68.112 in GM6, were also evaluated in addition to various response curves, like light intensities and temperature. We observed that light response curves show the saturation light intensity requirement of 1600 µmol for both the genotypes, whereas temperature response curves showed the optimum temperature requirement for Gz local as 20 °C and for GM6 it was found to be 35 °C. The results obtained for each individual parameter and other correlational studies indicate that IRGA forms a promising route for quick and reliable screening of various stress-tolerant valuable genotypes, forming the first study of its kind.

Main conclusion Our study demonstrated that the species respond non-linearly to increases in CO 2 concentration when exposed to decadal changes in CO 2 , representing the year 1987, 2025, 2051, and 2070, respectively. There are several lines of evidence suggesting that the vast majority of C3 plants respond to elevated atmospheric CO 2 by decreasing their stomatal conductance ( g s ). However, in the majority of CO 2 enrichment studies, the response to elevated CO 2 are tested between plants grown under ambient (380–420 ppm) and high (538–680 ppm) CO 2 concentrations and measured usually at single time points in a diurnal cycle. We investigated g s responses to simulated decadal increments in CO 2 predicted over the next 4 decades and tested how measurements of g s may differ when two alternative sampling methods are employed (infrared gas analyzer [IRGA] vs. leaf porometer). We exposed Populus tremula , Popolus tremuloides and Sambucus racemosa to four different CO 2 concentrations over 126 days in experimental growth chambers at 350, 420, 490 and 560 ppm CO 2 ; representing the years 1987, 2025, 2051, and 2070, respectively (RCP4.5 scenario). Our study demonstrated that the species respond non-linearly to increases in CO 2 concentration when exposed to decadal changes in CO 2 . Under natural conditions, maximum operational g s is often reached in the late morning to early afternoon, with a mid-day depression around noon. However, we showed that the daily maximum g s can, in some species, shift later into the day when plants are exposed to only small increases (70 ppm) in CO 2 . A non-linear decreases in g s and a shifting diurnal stomatal behavior under elevated CO 2 , could affect the long-term daily water and carbon budget of many plants in the future, and therefore alter soil–plant–atmospheric processes.

Leaves of the spiny winter annual express white patches (variegation) that can cover significant surface areas, the outcome of air spaces formed between the epidermis and the green chlorenchyma. We asked: (1) what characterizes the white patches in and what differs them from green patches? (2) Do white patches differ from green patches in photosynthetic efficiency under lower temperatures? We predicted that the air spaces in white patches have physiological benefits, elevating photosynthetic rates under low temperatures. To test our hypotheses we used both a variegated wild type and entirely green mutants. We grew the plants under moderate temperatures (20°C/10°C d/n) and compared them to plants grown under lower temperatures (15°C/5°C d/n). The developed plants were exposed to different temperatures for 1 h and their photosynthetic activity was measured. In addition, we compared in green vs. white patches, the reflectance spectra, patch structure, chlorophyll and dehydrin content, stomatal structure, plant growth, and leaf temperature. White patches were not significantly different from green patches in their biochemistry and photosynthesis. However, under lower temperatures, variegated wild-type leaves were significantly warmer than all-green mutants - possible explanations for that are discussed These findings support our hypothesis, that white variegation of leaves has a physiological role, elevating leaf temperature during cold winter days.

Foliar endophytic fungi (FEF) live within leaves without causing visible signs of disease. FEF occur in all vascular plants, yet the exact nature of interactions between specific FEF and their hosts is not well understood. Some FEF are associated with enhanced water use efficiency, nutrient acquisition, and defense. However, others may have negative effects under high-stress conditions. We examined a series of gas exchange traits in sweet birch (Betula lenta, Fagaceae) along an elevation gradient in the Pisgah National Forest Asheville, North Carolina, USA. From these leaves, we cultured surface-sterilized samples to examine FEF frequency and diversity. FEF cultures were categorized by morphotype and identified through analysis of internal transcribed spacer (ITS) sequences. FEF colonization frequency was 100% across all sites, and we identified 68 distinct morphotypes. Genetic identification of a subset of cultures suggests highly diverse FEF communities within this study system. Leaf gas exchange traits showed significant correlations with elevation at the site level, supporting the hypothesis that water stress increases with increasing elevation. However, further research is needed to determine associations between FEF communities and elevation. These findings, especially considering the limited sample size and small spatial scale of this study, indicate that the southern Appalachians are a promising region for future studies of FEF in forest systems.

ABSTRACT Oebalus poecilus is one of the most important pests of irrigated rice in Brazil. However, the impact of this species on the cultivar IRGA 424 RI, which is the most used, is unknown. Hence, the objective of this work is to evaluate the damage caused by O. poecilus on cv IRGA 424 RI. Panicles of this cultivar were infested for seven days at the R5 stage, using a randomized block design, considering the following factors sex, insect reproductive stage and insect density (number/panicle). In order to analyze the effect of these factors, the qualitative and quantitative damage caused by stink bugs to panicles were evaluated. An interaction was found between the sex and developmental stage for quantitative variables, in which reproductive females were responsible for increasing the damage in comparison to pre-reproductive females and the males, while the greatest qualitative damage was caused by reproductive insects regardless of sex and by females, despite the reproductive stage. Density of only one infesting insect has already increased the qualitative damage, while significant losses on the weight of the grain were verified with the infestation of two insects, demonstrating that IRGA 424 RI is susceptible to the attack of these stink bugs.

RuBisCo activase (Rca) is a catalytic chaperone involved in modulating the activity of RuBisCo (key enzyme of photosynthetic pathway). Here, we identified eight novel transcripts from wheat through data mining predicted to be Rca and cloned a transcript of 1.4 kb from cv. HD2985, named as TaRca1 (GenBank acc. no. KC776912). Single copy number of TaRca1 was observed in wheat genome. Expression analysis in diverse wheat genotypes (HD2985, Halna, PBW621, and HD2329) showed very high relative expression of TaRca1 in Halna under control and HS-treated, as compared to other cultivars at different stages of growth. TaRca1 protein was predicted to be chloroplast-localized with numerous potential phosphorylation sites. Northern blot analysis showed maximum accumulation of TaRca1 transcript in thermotolerant cv. during mealy-ripe stage, as compared to thermosusceptible. Decrease in the photosynthetic parameters was observed in all the cultivars, except PBW621 in response to HS. We observed significant increase in the Rca activity in all the cultivars under HS at different stages of growth. HS causes decrease in the RuBisCo activity; maximum reduction was observed during pollination stage in thermosusceptible cvs. as validated through immunoblotting. We observed uniform carbon distribution in different tissues of thermotolerant cvs., as compared to thermosusceptible. Similarly, tolerance level of leaf was observed maximum in Halna having high Rca activity under HS. A positive correlation was observed between the transcript and activity of TaRca1 in HS-treated Halna. Similarly, TaRca1 enzyme showed positive correlation with the activity of RuBisCo. There is, however, need to manipulate the thermal stability of TaRca1 enzyme through protein engineering for sustaining the photosynthetic rate under HS-a novel approach toward development of \"climate-smart\" crop.

In a volatile environment, a substantial number of sensor nodes are extensively dispatched to track and detect changes in physical environment. Although sensor nodes have limited energy resources, so energy-efficient routing is a major concern in Wireless Sensor Networks (WSN) to extend the network’s lifespan. Recent research shows that less throughput, increased delay, and high execution time have been provided with high energy usage. A new mechanism called the IRGA-MACS is proposed to overcome these inherent problems. Firstly, the Improved Resampling Genetic Algorithm (IRGA) is used for the best Cluster Head (CH) selection. Secondly, to assess the shortest path among CHs and nodes, the Modified Ant Colony Optimization based Simulated Annealing (MACS) has been speculated to minimize the time consumption during the transmission. The results show that the proposed approaches attain the supreme goal of increasing the network lifetime compared to existing methods.