Potassium fertilization improves growth, yield and seed quality of sunflower (Helianthus annuus L.) under drought stress at different growth stages

Detection of chlorine in potassium chloride and potassium sulfateusing chemical imaging and artificial neural network

Chlorine in potassium chloride and potassium sulfate must be detected due to its negative effect on soil. Although the laboratory-based chlorine measurement tests are reliable, they are time-consuming, expensive, and requires chemical agents and highly skilled operators. Therefore, the novelty of the present research is developing a fast, accurate, and cheap machine-based method to measure the amount of chlorine. The purpose of this research was to apply hyperspectral imaging and machine learning techniques to detect chlorine content in potassium chloride and potassium sulfate. Different percentages of chlorine in potassium chloride and potassium sulfate products were prepared with ranges of 53.1-50.05 and 1.47-2.13 %, respectively. Hyperspectral images were captured from the sample at the range of 400-950 nm. Mean, minimum, maximum, median, variance, and standard deviation features were extracted from the image channels corresponding to the effective wavelengths. The extracted features were classified using artificial neural network method and highest accuracy of the best models for potassium chloride and potassium sulfate were 95.6 and 94.4, respectively. The combination of hyperspectral imaging and machine learning promises reliable detection of chlorine content in potassium chloride and potassium sulfate in industrial systems with high speed and low cost.

Impact of aridity rise and arid lands expansion on carbon-storing capacity, biodiversity loss, and ecosystem services

Drylands, comprising semi-arid, arid, and hyperarid regions, cover approximately 41% of the Earth's land surface and have expanded considerably in recent decades. Even under more optimistic scenarios, such as limiting global temperature rise to 1.5°C by 2100, semi-arid lands may increase by up to 38%. This study provides an overview of the state-of-the-art regarding changing aridity in arid regions, with a specific focus on its effects on the accumulation and availability of carbon (C), nitrogen (N), and phosphorus (P) in plant-soil systems. Additionally, we summarized the impacts of rising aridity on biodiversity, service provisioning, and feedback effects on climate change across scales. The expansion of arid ecosystems is linked to a decline in C and nutrient stocks, plant community biomass and diversity, thereby diminishing the capacity for recovery and maintaining adequate water-use efficiency by plants and microbes. Prolonged drought led to a -3.3% reduction in soil organic carbon (SOC) content (based on 148 drought-manipulation studies), a -8.7% decrease in plant litter input, a -13.0% decline in absolute litter decomposition, and a -5.7% decrease in litter decomposition rate. Moreover, a substantial positive feedback loop with global warming exists, primarily due to increased albedo. The loss of critical ecosystem services, including food production capacity and water resources, poses a severe challenge to the inhabitants of these regions. Increased aridity reduces SOC, nutrient, and water content. Aridity expansion and intensification exacerbate socio-economic disparities between economically rich and least developed countries, with significant opportunities for improvement through substantial investments in infrastructure and technology. By 2100, half the world's landmass may become dryland, characterized by severe conditions marked by limited C, N, and P resources, water scarcity, and substantial loss of native species biodiversity. These conditions pose formidable challenges for maintaining essential services, impacting human well-being and raising complex global and regional socio-political challenges.

Regulation of an endophytic nitrogen-fixing bacteria GXS16 promoting drought tolerance in sugarcane

BACKGROUND

Drought limits crop growth and is an important issue in commercial sugarcane (Saccharum officinarum) production. Drought tolerance in sugarcane induced by endophytic nitrogen-fixing bacteria is a complex biological process that ranges from altered gene expression and cellular metabolism to changes in growth and productivity.

RESULTS

In this study, changes in physiological features and transcriptome related to drought tolerance in sugarcane conferred by the Burkholderia endophytic nitrogen-fixing bacterial strain GXS16 were investigated. Sugarcane samples inoculated with GXS16 exhibited significantly higher leaf relative water content than those without GXS16 inoculation during the drought stages. Sugarcane treated with GXS16 had lower levels of H2O2 and higher levels of abscisic acid than sugarcane not treated with GXS16 in the non-watering groups. Transcriptomic analysis of sugarcane roots identified multiple differentially expressed genes between adjacent stages under different treatments. Moreover, both trend and weighted correlation network analyses revealed that carotenoid biosynthesis, terpenoid backbone biosynthesis, starch and sucrose metabolism, and plant hormone signal transduction strongly contributed to the drought-tolerant phenotype of sugarcane induced by GXS16 treatment. Accordingly, a gene regulatory network including four differentially regulated genes from carotenoid biosynthesis (crtB, crtZ, ZEP and CYP707A) and three genes from terpenoid backbone biosynthesis (dxs, dxr, and PCME) was constructed.

CONCLUSIONS

This study provides insights into the molecular mechanisms underlying the application of GXS16 treatment to enhance drought tolerance in sugarcane, which will lay the foundation for crop development and improve productivity.

Salt and drought stress-mitigating approaches in sugar beet (Beta vulgaris L.) to improve its performance and yield

MAIN CONCLUSION

Although sugar beet is a salt- and drought-tolerant crop, high salinity, and water deprivation significantly reduce its yield and growth. Several reports have demonstrated stress tolerance enhancement through stress-mitigating strategies including the exogenous application of osmolytes or metabolites, nanoparticles, seed treatments, breeding salt/drought-tolerant varieties. These approaches would assist in achieving sustainable yields despite global climatic changes. Sugar beet (Beta vulgaris L.) is an economically vital crop for ~ 30% of world sugar production. They also provide essential raw materials for bioethanol, animal fodder, pulp, pectin, and functional food-related industries. Due to fewer irrigation water requirements and shorter regeneration time than sugarcane, beet cultivation is spreading to subtropical climates from temperate climates. However, beet varieties from different geographical locations display different stress tolerance levels. Although sugar beet can endure moderate exposure to various abiotic stresses, including high salinity and drought, prolonged exposure to salt and drought stress causes a significant decrease in crop yield and production. Hence, plant biologists and agronomists have devised several strategies to mitigate the stress-induced damage to sugar beet cultivation. Recently, several studies substantiated that the exogenous application of osmolytes or metabolite substances can help plants overcome injuries induced by salt or drought stress. Furthermore, these compounds likely elicit different physio-biochemical impacts, including improving nutrient/ionic homeostasis, photosynthetic efficiency, strengthening defense response, and water status improvement under various abiotic stress conditions. In the current review, we compiled different stress-mitigating agricultural strategies, prospects, and future experiments that can secure sustainable yields for sugar beets despite high saline or drought conditions.

Evolutionary analysis of the OSCA gene family in sunflower (Helianthus annuus L) and expression analysis under NaCl stress

Hyperosmolality-gated calcium-permeable channels (OSCA) are Ca^2 + nonselective cation channels that contain the calcium-dependent DUF221 domain, which plays an important role in plant response to stress and growth. However, the OSCA gene has not been fully identified and analyzed in sunflowers. In this study, we comprehensively analyzed the number, structure, collinearity, and phylogeny of the OSCA gene family in the sunflower, six Compositae species (Arctium lappa, Chrysanthemum morifolium, Cichorium endivia, Cichorium intybus, Lactuca sativa var. Angustata, and Carthamus tinctorius), and six other plants (soybean, Arabidopsis thaliana, rice, grape, and maize). The expression of the sunflower OSCA gene in nine different tissues, six different hormones, and NaCl stress conditions were analyzed based on transcriptome data and qRT-PCR. A total of 15 OSCA proteins, distributed on 10 chromosomes, were identified in the sunflower, and all of them were located in the endoplasmic reticulum. Using the phylogenetic tree, collinearity, gene structure, and motif analysis of the six Compositae species and six other plants, we found that the sunflower OSCA protein had only three subfamilies and lacked the Group 4 subfamily, which is conserved in the evolution of Compositae and subject to purification selection. The OSCA gene structure and motif analysis of the sunflower and six Compositae showed that there was a positive correlation between the number of motifs of most genes and the length of the gene, different subfamilies had different motifs, and the Group 4 subfamily had the smallest number of genes and the simplest gene structure. RNA-seq and qRT-PCR analysis showed that the expression levels of most OSCA genes in the sunflower changed to varying degrees under salt stress, and HaOSCA2.6 and HaOSCA3.1 were the most important in the sunflower's response to salt stress. The coexpression network of the sunflower genes under salt stress was constructed based on weighted gene co-expression network analysis (WGCNA). In conclusion, our findings suggest that the OSCA gene family is conserved during the sunflower's evolution and plays an important role in salt tolerance. These results will deepen our understanding of the evolutionary relationship of the sunflower OSCA gene family and provide a basis for their functional studies under salt stress.

El-Zohri M, Alajmi RA, Tahir M, Jawad R. Effect of temperature & humdity on population dynamics of insects' pest complex of cotton crop

The current study was directed to investigate the effect of temperature and humidity on insect pest complex of cotton. This study was carried out on the farmer field of a farmer of MouzaMehraywala tehsil and district Rajanpur southern part of the Punjab, Pakistan (29.1044° N, 70.3301° E) in the month of May, 2019 to November 2019. The climatic conditions of the study site were; a Rajanpur lie on 96m above sea level Rajanpur has a desert climate. During the year, there is virtually no rainfall. The average temperature in Rajanpur is 26.0°C | 78.8°F. Precipitation here is about 205 mm / 8.1 inch per year. Our results indicate that's the correlation of temperature (minimum and maximum), humidity (minimum and maximum), rainfall and weather condition (clear or cloud), it is clear that except temperature there is a positive correlation of jassid population. While among the relation of jassid with different factor there is very weak relation with jassid population regarding temperature (-0.001), the relation of humidity, rainfall and sky condition with jassid population is positive and moderate (0.520, 0.668 & 0.575 respectively), while the relation of jassid population among these factor is significant except temperature. The results indicate that's the correlation of temperature, humidity, rainfall and weather condition, it is clear that there is positive correlation of thrips population. While among the relation of thrips with different factor there is very weak relation of thrips population with temperature (.103), the relation of humidity, rainfall and sky condition with thrips population is positive and moderate (.515.751& .577 respectively), while the relation thrips population among these factor is significant except temperature. The results indicate that's correlation of temperature, humidity, rainfall and weather condition, it is clear that there is positive correlation of Whitefly population. While among the relation of Whitefly with different factors there is very moderate relation of Whitefly population with temperature (.076), the relation of humidity, rainfall and sky condition with Whitefly population is negative and moderate (-.051.-.368 & -.559 respectively), while the relation Whitefly population among these factor is significant except temperature.

Foliar Application of Potassium Mitigates Salinity Stress Conditions in Spinach (Spinacia oleracea L.) through Reducing NaCl Toxicity and Enhancing the Activity of Antioxidant Enzymes

Agronomic biofortification is the purposeful utilization of mineral fertilizers to increase the concentration of desired minerals in edible plant parts for enhancing their dietary intake. It is becoming crucial to enhance the dietary intake of K for addressing hidden hunger and related health issues such as cardiac diseases and hypertension. This study was designed to enhance the potassium concentration in edible parts of spinach through its foliar application under saline environment. The salinity levels of electrical conductivity (EC) = 4, 6, and 8 dS m−1 were applied using sodium chloride (NaCl) along with control. The levels of K for foliar sprays were 5 and 10 mM, along with control. The present experiment was performed under two factorial arrangements in a completely randomized design (CRD). After 60 days of sowing, the crop was harvested. Data regarding growth, ionic, physiological, and biochemical parameters, i.e., shoot dry weight, relative water content, electrolyte leakage, total chlorophyll content, tissue sodium (Na) and K concentration, activities of superoxide dismutase (SOD), and catalase (CAT) were recorded and those were found to be significantly (p ≤ 0.05) affected by foliar application of K on spinach under saline conditions. The highest growth, physiological and biochemical responses of spinach were observed in response to foliar-applied K at 10 mM. It is concluded that agronomic bio-fortification by foliar use of K can be a useful strategy to increase tissue K intakes and minimize Na toxicity in the vegetables studied under saline conditions.