Improvement of heat stress tolerance in soybean (Glycine max L), by using conventional and molecular tools

Genome-wide identification and characterization of NCED gene family in soybean (Glycine max L.) and their expression profiles in response to various abiotic stress treatments

The NCED (9-cis-epoxy carotenoid dioxygenase) enzyme regulates the biosynthesis of abscisic acid (ABA), which is responsible for plant growth, development, and response to various environmental challenges. However, no genome-wide identification, characterization, functional regulatory element analysis, and expression profiles in response to different abiotic stresses of the NCED gene family have yet to be investigated in an economically important legume plant species, soybean (Glycine max L.). Through comprehensive analysis, 16 NCED genes (named GmNCED1 to GmNCED16) belonging to the RPE65 domain were identified in the soybean genome and found to be unequally distributed over 9 distinct chromosomes. The distinct intron-exon structures of GmNCED genes were categorized into six groups and shared a close relationship with the grapevine. Segmental gene duplication events and the purifying selection process were evident in GmNCED genes, according to evolutionary studies. Cis-acting regulatory element analysis revealed that GmNCED genes were largely associated with light response as well as stress response. ERF, MYB, bZIP, and LBD emerged as the major transcription factors in GmNCED genes. The protein-protein interactions demonstrated the close relationship between GmNCED and Arabidopsis thaliana proteins, while micro-RNA analysis revealed the involvement of GmNCED genes in plant growth and development as well as in the regulation of abiotic stress. The expression profiles of GmNCED2, GmNCED11, and GmNCED12 provided evidence of their engagement in dehydration and sodium salt stress, whereas GmNCED14 and GmNCED15 were up-regulated in drought stress. Moreover, the up-regulation of GmNCED13 and GmNCED14 genes in heat tolerant germinated seed stages at high temperature delta region. More specifically, GmNCED14 might be used as a novel candidate gene under drought stress, and influencing seed germination at high temperature. Overall, this study identified the crucial role of GmNCED in conferring resistance against abiotic stress such as dehydration, salt, and drought, and also uncovering the detailed regulatory mechanism of ABA biosynthesis during seed germination.

Temperature-Dependent Modeling and Spatial Predictions for Identifying Geographical Areas in Brazil Suitable for the Use of Cordyceps javanica in Whitefly Control

Lalguard C99 WP, based on the Cordyceps javanica BRM 27666 strain, is registered in Brazil for whitefly control. Spatial prediction is crucial for optimizing its field use and efficacy. In this study, the optimal temperature for mycelial growth and conidial production of C. javanica is 25-30 °C, with no growth at 33-35 °C. The highest nymphal mortality occurred at 25 and 30 °C, showing lower LT50 values at 30 °C. Mycelial growth was similar at 15, 20, 25, 30, and 35 °C when the fungus was exposed for 6 h and then transferred to a 27.4 °C environment; however, growth was slower at 35 °C with daily 6 h exposure alternating over 18 h at room temperature (mean of 28.5 °C). When the second instar whitefly nymphs were exposed for 6 h or 6 h daily at 15, 20, 25, 30, and 35 °C, followed by 7 days at fluctuating temperatures (mean of 28.4-30.2 °C), nymphal mortality was similar across temperatures. Although other abiotic factors (solar radiation, humidity, rainfall, etc.) must be considered for fungal efficacy, spatial predictions based on fluctuating temperatures indicated that C. javanica is suitable for use throughout Brazil, though its performance varied at constant temperatures in different locations.

Enhancing Soybean (Glycine max L. Merr) Heat Stress Tolerance: Effects of Sowing Date on Seed Yield, Oil Content, and Fatty Acid Composition in Hot Climate Conditions

High temperatures can impede the growth and development of soybean plants, resulting in decreased yield and seed quality. Heat-induced damage can be mitigated by adjusting sowing date and selecting genotypes that are suitable for cultivation in hot climates. A 2-year (2017-2018) field experiment was conducted at Safiabad Agricultural and Natural Resources Research and Education Center, employing a split-plot design with three replications. The main plots were assigned three different sowing dates (June 22, July 6, and July 21), while the subplots featured eight soybean genotypes (SF1, SF2, SF3, SK93, M13, SG4, SG5, and Salend) belonged to IV to VI maturity groups. Temperature affected the fatty acid composition across all genotypes. Planting soybeans on June 22 and July 6 resulted in a 16% and 8% decrease in seed yield, respectively, compared to planting on July 21 over 2 years of experiments. SK93 exhibited the highest oil content (25.59%) when sown on the third date (July 21), whereas the SF3 genotype planted on June 22 displayed the lowest oil content (18.68%). Based on our findings, a decrease of approximately 0.33% in oil content and a 0.7% increase in protein content were observed with a one-degree temperature rise from 33°C during the seed-filling period. When the temperature ranged between 36°C and 38°C, the highest seed yield (2665-3008 kg.ha-1) was obtained, whereas the lowest seed yield (1940 kg.ha-1) occurred at 41.60°C. Delaying planting led to a higher seed yield (19.72%) and enhanced seed oil content (11.54%). The indeterminate growth genotype SK93 consistently showed the highest average seed yield (3231 kg.ha-1) over the 2-year experiment, exceeding other genotypes.

Recent advances of CRISPR-based genome editing for enhancing staple crops

An increasing population, climate change, and diminishing natural resources present severe threats to global food security, with traditional breeding and genetic engineering methods often falling short in addressing these rapidly evolving challenges. CRISPR/Cas systems have emerged as revolutionary tools for precise genetic modifications in crops, offering significant advancements in resilience, yield, and nutritional value, particularly in staple crops like rice and maize. This review highlights the transformative potential of CRISPR/Cas technology, emphasizing recent innovations such as prime and base editing, and the development of novel CRISPR-associated proteins, which have significantly improved the specificity, efficiency, and scope of genome editing in agriculture. These advancements enable targeted genetic modifications that enhance tolerance to abiotic stresses as well as biotic stresses. Additionally, CRISPR/Cas plays a crucial role in improving crop yield and quality by enhancing photosynthetic efficiency, nutrient uptake, and resistance to lodging, while also improving taste, texture, shelf life, and nutritional content through biofortification. Despite challenges such as off-target effects, the need for more efficient delivery methods, and ethical and regulatory concerns, the review underscores the importance of CRISPR/Cas in addressing global food security and sustainability challenges. It calls for continued research and integration of CRISPR with other emerging technologies like nanotechnology, synthetic biology, and machine learning to fully realize its potential in developing resilient, productive, and sustainable agricultural systems.

Revolutionizing soybean genomics: How CRISPR and advanced sequencing are unlocking new potential

Soybean Glycine max L., paleopolyploid genome, poses challenges to its genetic improvement. However, the development of reference genome assemblies and genome sequencing has completely changed the field of soybean genomics, allowing for more accurate and successful breeding techniques as well as research. During the single-cell revolution, one of the most advanced sequencing tools for examining the transcriptome landscape is single-cell RNA sequencing (scRNA-seq). Comprehensive resources for genetic improvement of soybeans may be found in the SoyBase and other genomics databases. CRISPR-Cas9 genome editing technology provides promising prospects for precise genetic modifications in soybean. This method has enhanced several soybean traits, including as yield, nutritional value, and resistance to both biotic and abiotic stresses. With base editing techniques that allow for precise DNA modifications, the use of CRISPR-Cas9 is further increased. With the availability of the reference genome for soybeans and the following assembly of wild and cultivated soybeans, significant chromosomal rearrangements and gene duplication events have been identified, offering new perspectives on the complex genomic structure of soybeans. Furthermore, major single nucleotide polymorphisms (SNPs) linked to stachyose and sucrose content have been found through genome-wide association studies (GWAS), providing important tools for enhancing soybean carbohydrate profiles. In order to open up new avenues for soybean genetic improvement, future research approaches include investigating transcriptional divergence processes, enhancing genetic resources, and incorporating CRISPR-Cas9 technologies.

Optimization of soybean physiochemical, agronomic, and genetic responses under varying regimes of day and night temperatures

Soybean is an important oilseed crop worldwide; however, it has a high sensitivity to temperature variation, particularly at the vegetative stage to the pod-filling stage. Temperature change affects physiochemical and genetic traits regulating the soybean agronomic yield. In this regard, the current study aimed to comparatively evaluate the effects of varying regimes of day and night temperatures (T1 = 20°C/12°C, T2 = 25°C/17°C, T3 = 30°C/22°C, T4 = 35°C/27°C, and T5 = 40°C/32°C) on physiological (chlorophyll, photosynthesis, stomatal conductance, transpiration, and membrane damage) biochemical (proline and antioxidant enzymes), genetic (GmDNJ1, GmDREB1G;1, GmHSF-34, GmPYL21, GmPIF4b, GmPIP1;6, GmGBP1, GmHsp90A2, GmTIP2;6, and GmEF8), and agronomic traits (pods per plant, seeds per plant, pod weight per plant, and seed yield per plant) of soybean cultivars (Swat-84 and NARC-1). The experiment was performed in soil plant atmosphere research (SPAR) units using two factorial arrangements with cultivars as one factor and temperature treatments as another factor. A significant increase in physiological, biochemical, and agronomic traits with increased gene expression was observed in both soybean cultivars at T4 (35°C/27°C) as compared to below and above regimes of temperatures. Additionally, it was established by correlation, principal component analysis (PCA), and heatmap analysis that the nature of soybean cultivars and the type of temperature treatments have a significant impact on the paired association of agronomic and biochemical traits, which in turn affects agronomic productivity. Furthermore, at corresponding temperature regimes, the expression of the genes matched the expression of physiochemical traits. The current study has demonstrated through extensive physiochemical, genetic, and biochemical analyses that the ideal day and night temperature for soybeans is T4 (35°C/27°C), with a small variation having a significant impact on productivity from the vegetative stage to the grain-filling stage.

Genome-Wide Identification and Expression Analysis of the VILLIN Gene Family in Soybean

The VILLIN (VLN) protein is an important regulator of the actin cytoskeleton, which orchestrates many developmental processes and participates in various biotic and abiotic responses in plants. Although the VLN gene family and their potential functions have been analyzed in several plants, knowledge of VLN genes in soybeans and legumes remains rather limited. In this study, a total of 35 VLNs were characterized from soybean and five related legumes. Combining with the VLN sequences from other nine land plants, we categorized the VLN gene family into three groups according to phylogenetic relationships. Further detailed analysis of the soybean VLNs indicated that the ten GmVLNs were distributed on 10 of the 20 chromosomes, and their gene structures and protein motifs showed high group specificities. The expression pattern analysis suggested that most GmVLNs are widely expressed in various tissues, but three members have a very high level in seeds. Moreover, we observed that the cis-elements enriched in the promoters of GmVLNs are mainly related to abiotic stresses, hormone signals, and developmental processes. The largest number of cis-elements were associated with light responses, and two GmVLNs, GmVLN5a, and GmVLN5b were significantly increased under the long light condition. This study not only provides some basic information about the VLN gene family but also provides a good reference for further characterizing the diverse functions of VLN genes in soybeans.