Cold stress effects on morpho-physiological traits in chickpea (<i>Cicer arietinum</i> L.) genotypes at early developmental stages

Chickpea, often called the "poor man's meat," is a vital, protein-rich crop grown globally. It serves as a low-cost alternative to animal-based protein and enhances soil quality through nitrogen fixation. However, chickpea cultivation faces challenges, particularly cold stress during early growth stages, which can lower yields. This study focused on understanding how two main chickpea types, Desi and Kabuli, respond to cold temperatures during the seedling stage to identify traits that could aid in breeding cold-tolerant varieties.The research involved testing 22 genotypes at both normal (23°C) and suboptimal (15°C) temperatures. Cold stress significantly reduced growth across all genotypes, especially affecting shoot and root weights. However, Desi types performed better under cold conditions compared to Kabuli types. Six varieties were then selected for further analysis of their root and physiological traits.Cold temperatures severely inhibited early root growth, particularly the lateral roots. However, early root development did not predict cold tolerance during later growth stages. Detailed root analysis revealed that Desi varieties had beneficial traits, such as a greater number of lateral roots, larger lateral root diameter, and thicker root vessels, which appeared to contribute to their cold tolerance.Additionally, the physiological responses between one Desi and one Kabuli variety showed that Desi types had higher photosynthesis rates, less chlorophyll damage, and better growth under cold stress. These findings suggest that selecting for specific root and physiological traits could enhance cold tolerance in chickpeas, though further research is needed to develop cold-resistant varieties

Approaches in Enhancing Antioxidant Defense in Plants

This Special Issue, “Approaches in Enhancing Antioxidant Defense in Plants” published 13 original research works and a couple of review articles that discuss the various aspects of plant oxidative stress biology and ROS metabolism, as well as the physiological mechanisms and approaches to enhancing antioxidant defense and mitigating oxidative stress. These papers will serve as a foundation for plant oxidative stress tolerance and, in the long term, provide further research directions in the development of crop plants’ tolerance to abiotic stress in the era of climate change

A study of saponins in legumes of importance to both human and animal nutrition

This work describes the analysis and isolation of saponins using a range of chromatographic techniques, the development of a quantitative HPLC method for the determination of saponins as they occur in seed, and the study of various factors which affect both the saponin content and composition in different legume seeds.Seed from 6 cultivars of lupin were grown in 4 regions of Australia, with up to 15 plots sampled within each region. Saponin contents ranged from 0 to 740 mg kg-1. Soyasaponin I, soyasaponin VI (the 2, 3-dihydro-2,5-dihydroxy-6-methyl-4H/-pyran-4-one conjugate of soyasaponin I) and a new saponin were found in the lupin seed. The changes observed in saponin content were dependent on cultivar, followed by the site and then the region where grown.The saponin content of 20 cultivars of lentils grown in Spain ranged from 654 to 1269 mg kg-k Soyasaponins I and VI were present in all the cultivars. The saponin content depended on both seed size and testa colour.The use of a mild extraction technique and an improved quantitative HPLC method showed soyasaponin VI to be the only saponin present in lupin seed whereas soyasaponin I was derived from soyasaponin VI when harsher extraction conditions were used.The HPLC method was used to study the effect of soaking, cooking and germination on the saponin content and composition of two cultivars of both chickpeas and lentils. Soyasaponin VI was the only saponin detected in the unprocessed, soaked and germinated seed. Neither soaking nor germination modified the saponin content or composition of chickpeas and lentils. Soyasaponin VI was partially degraded during cooking into soyasaponin I, and both leached into the cooking solution. An overall loss of saponin content was found for lentil but none for chickpea

Study of Antifungal, Anti-aflatoxigenic, Antioxidant Activity and Phytotoxicity of Algerian Citrus limon var. Eureka and Citrus sinensis var. Valencia Essential oils

The inhibitory influence of Citrus limon var. Eureka and Citrus sinensis var. Valencia essential oils (EOs) on the growth of Aspergillus flavus and AFB1 production was evaluated. The EOs were characterized by limonene (54.95% and 82.6%, respectively) as predominant component. Citrus limon EO at 1.75 mg/mL and Citrus sinensis at 2 mg/mL could totally inhibit fungal growth as well as AFB1 production. The Citrus EOs revealed wide spectrum of fungitoxicity against some isolated fungi in terms of MIC and MFC. On the other hand, the antioxidant activity was also assessed where IC50 and ß-carotene/linoleic acid inhibition percentage of Citrus limon and Citrus sinensis oils were 1570.10 and 752.26 µg/mL, 36.19 and 55.56%, respectively, while the total phenolic were 16.90 and 10.53 µg/mg, respectively. Additionally, the EOs showed their non phytoxicity on wheat seeds. These findings demonstrated that EOs could be good alternatives to protect food

Subcellular Proteomics: Application to Elucidation of Flooding-Response Mechanisms in Soybean

Soybean, which is rich in protein and oil, is cultivated in several climatic zones; however, its growth is markedly decreased by flooding. Proteomics is a useful tool for understanding the flooding-response mechanism in soybean. Subcellular proteomics has the potential to elucidate localized cellular responses and investigate communications among subcellular components during plant growth and during stress. Under flooding, proteins related to signaling, stress and the antioxidative system are increased in the plasma membrane; scavenging enzymes for reactive-oxygen species are suppressed in the cell wall; protein translation is suppressed through inhibition of proteins related to preribosome biogenesis and mRNA processing in the nucleus; levels of proteins involved in the electron transport chain are reduced in the mitochondrion; and levels of proteins related to protein folding are decreased in the endoplasmic reticulum. This review discusses the advantages of a gel-free/label-free proteomic technique and methods of plant subcellular purification. It also summarizes cellular events in soybean under flooding and discusses future prospects for generation of flooding-tolerant soybean

Functional Analysis of Two Brassinosteroid Responsive, Putative Calmodulin-Binding Proteins 60 (CBP60S) in Arabidopsis Thaliana

Brassinosteroids (BRs) have remarkable ability to increase stress tolerance in plants. Investigations to understand the molecular mechanisms underlying BR-mediated stress tolerance resulted in identification of genes belonging to the family calmodulin binding protein X (CBPX). The present study was focused on studying the role of CBPX1 and CBPX2 in BR mediated stress tolerance and functional characterization using a reverse genetic approach. The upregulation of CBPX1 and CBPX2 by BR and stress noted in publicly available AtGenexpress datasets and by qRT-PCR analysis strongly suggests that these are BR responsive genes and functional analysis of T-DNA insertion mutants showed salt stress related functions in A. thaliana. The T-DNA insertion mutants cbpx1 and cbpx2 were sensitive to salt stress compared to WT, while CBPX1 OE lines showed increased salt tolerance. The results of the present study have revealed two new stress related genes, CBPX1 and CBPX2 that displayed increased expression in response to BR and salt stress, and also play an important role in conferring salt stress tolerance to plants. CBPX1 also plays an important role in determining the root length in A. thaliana

Food Legumes and Rising Temperatures: Effects, Adaptive Functional Mechanisms Specific to Reproductive Growth Stage and Strategies to Improve Heat Tolerance

Ambient temperatures are predicted to rise in the future owing to several reasons associated with global climate changes. These temperature increases can result in heat stress- a severe threat to crop production in most countries. Legumes are well-known for their impact on agricultural sustainability as well as their nutritional and health benefits. Heat stress imposes challenges for legume crops and has deleterious effects on the morphology, physiology, and reproductive growth of plants. High-temperature stress at the time of the reproductive stage is becoming a severe limitation for production of grain legumes as their cultivation expands to warmer environments and temperature variability increases due to climate change. The reproductive period is vital in the life cycle of all plants and is susceptible to high-temperature stress as various metabolic processes are adversely impacted during this phase, which reduces crop yield. Food legumes exposed to high-temperature stress during reproduction show flower abortion, pollen and ovule infertility, impaired fertilization, and reduced seed filling, leading to smaller seeds and poor yields. Through various breeding techniques, heat tolerance in major legumes can be enhanced to improve performance in the field. Omics approaches unravel different mechanisms underlying thermotolerance, which is imperative to understand the processes of molecular responses toward high-temperature stress

Nutrient seed treatments to improve abiotic stress tolerance in Brassica napus L.

Poor germination and limitations during early plant growth are widespread constraints for oilseed rape (OSR; Brassica napus L.) with increasing importance due to a rising frequency of weather extremes related with global climate change. In this study, efforts have been made to improve health and stress resistance of OSR by exploring perspectives of cost-effective application techniques for micronutrients with stress- protective functions to cover increased demands of these nutrients under stress conditions. After preliminary screening experiments, special emphasis was placed on zinc (Zn) seed treatments including seed priming (SP) and seed dressing (SD). Effects on seedling performance during early growth were recorded at optimal conditions for plant growth in terms of temperature, nutrient and water supply and also under drought stress for winter OSR and under low root zone temperature (RZT) stress in spring OSR. Accordingly, both, ZnSP and ZnSD may offer practical, economically low-cost application methods to improve early seedling establishment particularly under challenging environmental conditions, to improve the perspectives for conversion into higher economic yields and could be equally attractive for small-scale on-farm use and rape seed industry.Reduzierte Keimung und Einschränkungen in der Jugendentwicklung sind weitverbreitete Probleme im Rapsanbau, die aufgrund einer durch den Klimawandel bedingten Erhöhung der Häufigkeit von Witterungsextremen zunehmend an Bedeutung gewinnen. In der vorliegenden Arbeit wurden daher Perspektiven für die kostengünstige Anwendung von Mikronährstoffen mit Schutzwirkungen gegen Stressfaktoren untersucht, um einen erhöhten Bedarf dieser Nährstoffe unter Stressbedingungen nach Möglichkeit auszugleichen. Basierend auf den Ergebnissen einführender Screeningversuche. wurden bevorzugt Ansätze zur Saatgutbeizung und zum Saatgutpriming, sowohl unter optimalen Anzuchtbedingungen im Hinblick auf Temperatur, Wasser und Nährstoffangebot sowie Trockenstressbehandlungen bei Winterraps untersucht, während der Einfluss niedriger Wurzelraumtemperaturen bei Sommerraps betrachtet wurde. Sowohl Zn-Saatgutpriming als auch Zn-Saatgutbeizung könnten also praktische und ökonomisch günstige Ansätze bieten, um die Keimlingsentwicklung besonders unter abiotischen Stressbedingungen zu fördern, als Grundlage für eine optimierte Bestandsentwicklung und verbesserte Ertragsbildung. Die Methoden bieten Perspektiven sowohl für direkte On-Farm Anwendungen als auch für großtechnische Ansätze in der Saatgutindustrie

Effect of heat stress on pollen development and seed set in field pea (Pisum sativum L.)

Pea (Pisum sativum L.) is a major legume crop grown in a semi-arid climate in western Canada, where heat stress often causes flower abortion and reduces yield. Heat specifically affects pollination and seed set, the processes associated with pollen fertilizing an ovule to form an embryo, and seed development. The goals of this research were to investigate the effect of heat stress on pollen development, function, and seed set, and to identify single nucleotide polymorphism (SNP) markers associated with reproductive development traits via association mapping. Heat stress reduced pollen viability, the proportion of ovules that received a pollen tube, seed number per pod, and the seed-ovule ratio in a pod when exposed to 35/18°C day/night temperatures for 4-7 days. Heat stress also reduced ovule viability with P = 0.09. High temperature reduced in vitro pollen germination by approximately 30% in CDC Sage and 55% in CDC Golden when the 10-h incubation temperature increased from 24 °C to 36 °C. Pollen wall (intine) thickness increased by 46% from 222 nm to 414 nm as a result of heat stress, and anther dehiscence failed to occur following exposure to 35/18°C day/night for 7 days. The lipid region of the pollen coat and exine of CDC Sage was more stable compared to CDC Golden, which may explain the greater robustness of CDC Sage pollen to elevated temperature. Timing of flower appearance and age of the two flowers is sequential on a nodal raceme, and nodes and flowers along the main stem are also sequential. Heat stress impacted young, barely visible floral buds in the developing inflorescence apex more than more advanced buds and open flowers. The flower abortion rate was greater when plants were exposed to heat stress and when young flower buds were visible at the first reproductive node (T1) compared to the development stage when flowers at the second reproductive node were fully open (T2). Similarly, seed-set, pod development, and seed yield were more negatively affected when high temperature exposure started at T1 compared to T2. Seed development was negatively impacted by the pollen interaction with pistil under heat stress, such as anther indehiscence and fewer ovules evidently fertilized. Heat stress accelerated seed abortion in all ovule positions within pods. In half of the cultivars tested, ovules at the pod’s medial and stylar-end positions were more likely to develop into seeds compared to basal ovules. Cultivars with small seed-size such as ‘40-10’ and ‘Naparnyk’ were able to retain the most ovules and seeds per pod compared to large seed size cultivars, and large-seeded cultivars like ‘MFR043’ aborted seeds when exposed to heat. Population structure analysis was conducted on a panel of 92 diverse pea varieties, and they clustered into three subpopulations mainly consistent with their geographical origins. Association analyses identified 60 single nucleotide polymorphisms (SNPs) significantly associated with reproductive development related traits including days to flowering (DTF), duration of flowering (DOF), number of reproductive nodes, number of pods on the main stem, pod set potential, percentage of pod set, and pollen germination reduction due to heat stress. Among these 60 marker-trait associations, 33 SNPs were associated with the onset of flowering, 8 SNPs with pod development, and 19 SNPs with the number of reproductive nodes. Twelve SNPs associated with DTF and 2 SNPs associated with DOF overlapped with the SNP markers associated with the number of reproductive nodes. However, markers associated with in vitro pollen germination were not found due to the variability in sampling 92 genotypes. The findings obtained from this research will benefit plant physiologists and plant breeders for a better understanding of successful reproductive development in field pea and other legume crops experiencing increasing temperatures due to global climate change