Protoplasma最新文献

The Malpighian tubules are well-known and studied as the principal excretory organs in most insects. They play a key role in the production of primary urine and osmoregulation. It works with the rectum while regulating the water and salt balance in the body. The distal ends of the tubules are found in contact with the wall of the rectum in insects that feed on dry substances or live in a nearly dry environment and therefore, need to retain water: that is an arrangement known as a cryptonephric system. In this study, Cassida palaestina Reiche, 1858 is a beetle species belonging to the order Coleoptera was used as material, and the morphological features of the Malpighian tubules of this species were examined using light microscopy and scanning electron microscopy. The four cryptonephric Malpighian tubules of C. palaestina are found at the junction of the midgut and hindgut. The apical surface of tubule cells is surrounded by numerous microvilli. The cytoplasm of tubule cells fills with granules of many different sizes. Here, we reported our observations on the cryptonephridial complex in C. palaestina, and this study is almost the first study to examine the structure of the excretory system of the genus Cassida. Insights into the structure of the cryptonephridial complex of this species are compared with the well-studied cryptonephridial complexes of Cucujiformia. The findings were found to be quite similar to those of other species studied in the literature (with the structure of the Malpighian tubules of insects within the same order and from different orders). These data are the basis for future morphological studies. At the same time, the presence or absence of the cryptonephridial complex among species in the Cucujiformia infraorder, which C. palaestina is a part of, helps to understand the phylogenetic relationship.

This special mini-review was planned as a synthesis of current understanding of the role of tapetum and orbicules, of the knowledge on pollenkitt, with addition of our own data on experimental orbicule simulation. The aim was to show the development of knowledge and ideas through time. Tapetum types are so changeable that the idea of norm becomes ghostly. The review is based on our own and other authors' results. Cyclic-invasive tapeta, surprising exine-like tapetal surface, direct connections of tapetum with microspores via filaments are probably not rare phenomena. Our in vitro experiments on microspore exine simulations, which have led also to appearance of orbicule-like structures, support the view of their by-product nature, based on self-assembly. Different types of orbicules and their development are examined. Tapetum and orbicule functions and especially pollenkitt production are reviewed, together with the data on sporopollenin. Some concise data on molecular and genetic studies are added.

Drought stress severely impacts mung bean [Vigna radiata (L.) R. Wilczek] production, making exploration of drought tolerance and breeding strategies critical. This study investigated drought resistance mechanisms in ten mung bean cultivars under polyethylene glycol (PEG 6000)-induced water deficit, analyzing germination, morphology, and physiology. Drought impaired vigor index (VI) and seedling growth across all cultivars, with mung bean Bing 20 exhibiting reduced VI (76.28%) and seedling length (63.47%). Drought induced hydrogen peroxide (H₂O₂) bursts, exacerbating membrane lipid peroxidation and elevating malondialdehyde levels, wherein increased H₂O₂ content in Bing 18 (2.02-fold) and elevated malondialdehyde content in Bing 17 (36.64%). Mung bean activated superoxide dismutase, peroxidase, and catalase antioxidant enzymes to mitigate oxidative damage and enhanced seed vigor by upregulating amylase and osmolyte accumulation (soluble sugar, starch, soluble protein, and proline); α-amylase activity in Jin 8 was elevated by 1.68-fold, while Jin 1 exhibited increased starch (1.57-fold) and proline content (40.28-fold). Based on drought resistance coefficients derived from these traits, correlation and principal component analyses (PCA) were performed. Mung bean Jin 1, Jin 7, Jin 8, Bing 11, and Bing 18 were identified as relatively tolerant, whereas Bing 16, Bing 17, Bing 19, Bing 20, and Bing 21 exhibited greater susceptibility. Correlation analysis revealed contrasting metabolic strategies tolerant varieties prioritized rapid early growth, while susceptible varieties showed a complex balance of growth, defense, and osmotic adjustment. PCA identified germination index and seedling length as key drought resistance screening traits. These findings enhance understanding of drought tolerance and facilitate selection of varieties. HIGHLIGHTS: Drought tolerance of ten mung bean cultivars was comprehensively evaluated based on germination, morphological, and physiological profiles under PEG-induced stress. Distinct drought response strategies were revealed between tolerant (prioritizing rapid early growth) and susceptible (balancing growth, defense, and osmotic adjustment) mung bean varieties. Germination index and seedling length were identified as key indicators for screening drought-tolerant mung bean varieties.

The genus Rhododendron, comprising approximately 1200 species, is the largest within its family and possesses significant ornamental value. However, functional genomics studies in this genus are hampered by an inefficient Agrobacterium-mediated stable transformation system. To facilitate rapid gene function verification, we developed a protoplast-based transient expression system using petal tissues. We optimized the enzymatic hydrolysis conditions (2.0% cellulase, 1.00% macerozyme, 0.6 mol/L mannitol, 8-h digestion) and established a two-step purification protocol involving centrifugal precipitation followed by flotation. For polyethylene glycol (PEG)-mediated transformation, the optimal parameters were 40% PEG4000, 0.10 mol/L CaCl₂, 35 °C, 25 μg of plasmid, and a 20-min incubation. The system's feasibility for subcellular localization was confirmed by expressing HSFC1a-eGFP and RCI2B-eGFP fusion proteins in R. pulchrum protoplasts. Furthermore, qRT-PCR analysis showed that the transcript levels of HSFC1a and RCI2B peaked at 12 h post-transformation, demonstrating time-dependent expression dynamics.

Sideroxylon obtusifolium (Humb. ex Roem. & Schult.) T.D. Penn. is a tree species belonging to the Sapotaceae family, whose black berries can be consumed fresh or as jam. It is widely distributed in Mexico, Belize, Costa Rica, Venezuela, Bolivia, Brazil, Paraguay, Argentina, and Uruguay. While previous studies have focused on describing its floral biology, the development of the ovule and pollen has not been studied from an anatomical point of view. To provide further insights into the sexuality of this fruit tree, we conducted a study of the processes of sporogenesis and gametogenesis using conventional plant anatomical techniques. Flowers of different sizes were fixed in FAA, embedded in paraffin, sectioned, and stained with Safranin-Astra Blue for light microscopy. The processes of sporogenesis and gametogenesis result, on the one hand, in the anatropous, unitegmic, and tenuinucellate ovule, with a Polygonum embryo sac. On the other hand, it gives pollen grains that are released as monads in a tricellular state. This study provides anatomical data not previously described for this species and is part of the embryological studies that are currently being carried out in different species of fruit trees in South America. These findings enhance the embryological understanding of Sapotaceae and offer a foundation for future research in systematics, phylogeny, and conservation biology of Sapotaceae.

This study examined the influence of exogenous gamma-aminobutyric acid (GABA) on drought tolerance in faba bean (Vicia faba) under 15% PEG-induced drought stress conditions. Faba bean plants were subjected to treatments with varying GABA concentrations (0.5, 1, and 2 mM) to evaluate physiological, biochemical, and molecular responses to drought stress. The results indicated that a concentration of 0.5 mM GABA significantly enhanced the photosynthetic rate, stomatal conductance, and chlorophyll content, while also markedly improving relative water content (RWC). At this concentration, GABA treatment mitigated oxidative damage, evidenced by reduced levels of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), and increased antioxidant enzyme activities (catalase, superoxide dismutase, and ascorbate peroxidase). Furthermore, GABA supplementation influenced the accumulation of proline and soluble sugars, thereby facilitating osmotic regulation and stress adaptation. Gene expression analysis revealed that GABA modulated key drought-responsive genes, notably enhancing the expression of those associated with antioxidant defenses (VfCAT, VfSOD, VfAPX), water transport (VfPIP), and osmoprotection (VfP5CDH), particularly in leaf and root tissues, with differential effects observed across GABA concentrations. Interestingly, higher concentrations of GABA (1 and 2 mM) yielded reduced or inconsistent outcomes, suggesting the existence of an optimal concentration threshold for stress mitigation. Collectively, these findings underscore the potential of GABA as a beneficial agent for enhancing drought resilience in faba bean, providing a promising strategy to improve crop tolerance to water scarcity.

Cadmium (Cd) pollution has emerged as a critical global environmental concern due to its significant toxicity, environmental persistence, and the pervasiveness of contamination. In recent years, essential oils (EOs) have been recognized as a promising, environmentally friendly substitute for traditional chemical treatments to counteract metal toxicity in plants. Moreover, these naturally derived compounds improve plant resilience when facing challenging environmental conditions. This study explores the potential of EOs extracted from the aerial tissues (flowering shoots and leaves) of the halophyte plant Lobularia maritima to alleviate Cd toxicity in durum wheat exposed for 10 days to 30 µM CdCl₂. GC-MS analysis revealed that L. maritima essential oil (LmEO) was predominantly composed of oxygenated monoterpenes (74.40%). The impact of various LmEO concentrations (2, 4, 6, and 8 ppm) on seed germination and early growth of durum wheat identified 4 ppm as the most effective. Application of LmEO (at 4 ppm) significantly enhanced seedling tolerance to Cd by promoting growth, reducing Cd accumulation in shoots by approximately 41%, and malondialdehyde content (a marker membrane damage) by 43% compared to the Cd-stressed plants. LmEO treatment also reduced oxidative stress by boosting antioxidant enzyme activity and reducing ROS accumulation. Furthermore, RT-qPCR analysis of six genes encoding heavy metal transporters in roots (TdNRAMP, TdHMA5, TdHMT1, TdZIF1, TdZIFL2, and TdZTP29) revealed that several key genes were upregulated by approximately twofold in durum wheat seedlings treated with LmEO, suggesting a potential link to improved Cd tolerance. Our findings suggest that exogenous LmEO application is associated with enhanced Cd stress resilience through reduced metal accumulation and improved antioxidant defense in durum wheat. These results indicate the potential of LmEO as a natural biostimulant to improve crop growth in contaminated soils.

Northeast India, a global biodiversity hotspot, harbors exceptional plant diversity within the Indo-Burma region. This study provides the first comprehensive integration of floristic, ecological, and genomic analyses of angiosperm diversity in North Guwahati, Assam, using the Indian Institute of Technology Guwahati campus as a model semi-natural landscape. Systematic year-long surveys recorded 434 angiosperm species belonging to 312 genera and 101 families, including 70 trees, 86 shrubs, and 244 herbs (with 31 climbers and a few aquatics). Poaceae was the most species-rich family (34 species), followed by Fabaceae (29) and Cyperaceae (26), reflecting typical tropical diversity. Spatial analysis revealed strong habitat-specific species distribution, with open plains supporting the highest diversity (206 species) and forest edges harboring rare taxa. Community structure across four ecological zones showed significant spatial heterogeneity, with Zone 1 having the highest Shannon-Wiener diversity (H' = 4.084) and Zone 4 the highest evenness (E = 0.905). Nuclear DNA content (2C values) was estimated via flow cytometry for 110 species, contributing 58 novel genome size records and revealing a 98-fold variation (0.43-42.5 pg). Monocots had significantly larger genomes than dicots (4.79 vs. 1.63 pg, p < 0.001), and ecological trends showed a progressive increase in genome size from herbaceous (1.93 pg) to woody forms (2.50 pg), supporting the large genome constraint hypothesis. GIS mapping integrated taxonomic, ecological, and genomic data, uncovering spatial patterns in diversity and genome evolution. region. This comprehensive framework provides a crucial foundation for assessing biodiversity and guiding conservation efforts in this ecologically important region.

H₂S is a lipophilic gaseous molecule with the characteristic pungent "rotten egg" odour. Studies have shown that H₂S at lower concentrations acts as a gasotransmitter, providing evidence for its crucial role in plant growth, development and stress responses. The present work underlies the effects of moderate and high concentrations of NaCl stress and two concentrations of NaHS (H₂S donor) on certain metabolic signatures of tomato seedlings. In this study, tomato seedlings were grown under different NaCl concentrations (0 mM, 40 mM, 80 mM and 120 mM) and three concentrations of H₂S, i.e. T0 (0 µM), T1 (25 µM) and T2 (100 µM) were applied exogenously. The results showed a reduction in MDA content, electrolytic leakage, Na⁺/K⁺ ratio, and proline content in tomato seedlings with exogenous application of H₂S under NaCl stress. On the contrary, exogenous H₂S application at T2 concentration increased chlorophyll content, RWC, endogenous H₂S content, L-DES activity and ascorbate content under 80 mM NaCl stress. Concomitantly, exogenous H₂S treatment, particularly at T2 concentration, upregulated the antioxidative enzyme activity like glutathione reductase (GR), catalase (CAT), ascorbate peroxidase (APOD), peroxidase (POD) and superoxide dismutase (SOD) in NaCl-treated tomato seedlings. These results indicate that exogenous H₂S application, especially at T2 concentration, imparts a higher amount of alleviation in salt-stressed tomato seedlings grown under 80 mM NaCl. Thus, a concentration-dependent interaction of NaCl stress and H₂S signaling appears to be mediated through long-distance signaling in tomato seedlings.