Acta Physiologiae Plantarum最新文献

Salinity is a major abiotic stressor that impedes plant growth and negatively affects crop yield. However, Arbuscular mycorrhizal fungi (AMF) can establish a symbiotic relationship with over 80% of terrestrial plant roots. This relationship ultimately results in increased plant growth, improved plant stress resistance, and, consequently, a promising agricultural production and environmental protection solution. The aim of this experiment was to evaluate the impact of arbuscular mycorrhizal fungi on the photosynthetic physiology of strawberries under salinity stress. The greenhouse experiment involved the strawberry cultivar ‘Benihoppe’, which was inoculated with Glomus mosseae under three salt stress levels (0 mM, 30 mM, and 60 mM). Subsequently, the results showed that salinity stress led to a significant decline in leaf area, fresh biomass, and photosynthetic characteristics of the strawberries. Under salt stress, especially at the concentration of 60 mM. Pn, Gs, Tr, Ci, Fv/Fm, and NPQ showed significant differences. After inoculation of AMF, arbuscular mycorrhiza established a beneficial symbiotic relationship with strawberry roots, which effectively reduced salt damage and promoted the growth of strawberry plants. Leaf area, fresh biomass, and relative chlorophyll content were significantly increased. Pn, Tr, and Gs of mycorrhizal strawberry were significantly higher than those of control group. In addition, the light energy conversion efficiency of strawberry plants inoculated with AMF was improved, thus increasing the potential photosynthetic capacity and photosynthetic rate of strawberry.

Freshly harvested marigolds face a principal challenge of limited storability, typically 2–3 days, due to high perishability. In this study, an effort was made to identify optimal packaging material to prolong flower storability while preserving their quality under ambient (30 ± 2 °C) and cold (5 ± 1 °C) storage environments. Researchers tested five packaging materials, viz., muslin cloth, polypropylene woven bag, low-density polyethylene (LDPE), high-density polyethylene (HDPE) and cryovac® shrink-wrap in a factorial Completely Randomized Design. Shrink-wrap and HDPE are identified as the most effective alternatives against conventional packing material, extending storability to 19.0 and 18.5 days, respectively, in cold storage environment. Shrink-wrapped marigold flowers showed the longest storability of 4.5 days and 19.0 days under ambient and cold storage, respectively. The shrink-wrap also maintained flower diameter, brightness, moisture content, membrane stability index, carotenoid content and antioxidant enzyme activity, while reducing shrivelling, weight loss, and respiration rate. Enzyme activity of superoxide dismutase (0.70 Ug⁻¹ and 0.60 Ug⁻¹), catalase (1.28 Ug⁻¹ and 0.99 Ug⁻¹) and guaiacol peroxidase were highest under ambient and cold storage conditions, respectively at senescence and resulted in consequent delay of senescence. This study underscores the significant impact of shrink-wrap, not only on improving storability but also on preserving the physiological and biochemical attributes of marigold flowers over an extended period.

The cultivated strawberry is a vital economic crop grown extensively worldwide. Recently, there has been more focus on breeding strawberry cultivars that produce high-quality fruit. Anthocyanin is a crucial determinant of the quality of strawberries. Transcriptome analysis of fruits at various development stages of the ‘Yanli’ cultivar was performed to examine the mechanisms of anthocyanin accumulation in the process of fruit development of cultivated strawberries. We screened 33,617 differentially expressed genes whose average expression value was more significant than 2 in at least one sample. We classified these differentially expressed genes into nine categories based on k-mean clustering analysis. Furthermore, we recognized that anthocyanin synthesis-related genes’ promoter regions had a high consistency of conserved motifs with a similar expression pattern. By conducting a correlation analysis between seven anthocyanin pathway genes and various transcription factors, we identified 560 transcription factors that might be involved in the anthocyanin biosynthesis pathway. In summary, we can identify a more significant number of prospective transcription factors in the anthocyanin pathway based on the haplotype-resolved genome of ‘Yanli’.

The effect of short-term high (+ 40 °C, 2 h) (HT) and positive low-temperature (+ 4 C, 2 h) (LT) stresses on leaf micromorphology and ultrastructure of mesophyll cells in winter rye was investigated. After HT, leaf blade relief became reticulate, while under control conditions and after low-temperature stress, leaf blade relief was folded. The ultrastructure of the leaf mesophyll cells of control plants was nominal: in the chloroplasts of regular lenticular shape, a well-developed thylakoid system immersed in a fine-grained stroma was clearly visible. Short-term HT caused the destruction of thylakoid membranes. A wave-like packing of granal thylakoids, a significant expansion of the lumenal spaces, and a disruption of the structural connection between the granal and stroma thylakoids were noted. There was an accumulation of lipid drops in the cytoplasm. LT stress caused intensive formation of plastoglobules, a decrease in the number and size of starch grains in the chloroplasts. Destruction of thylakoid membranes was not seen. After HT stress, the mitochondria noticeably "swelled", and the membranes of the cristae became less contrasting. After LT stress, significant changes occurred in the morphology of organelles: some of the mitochondria kept a round shape, but some acquired a lenticular or "dumbbell" shape. It was found that, depending on the type of temperature exposure, various adaptive programs are implemented in plant cells, which are accompanied by a complex of ultrastructural changes, thanks to which plants are able to successfully tolerate short-term exposure to stressful temperatures during active vegetation.

Bletilla striata is a perennial herb of the orchid family with its tubers frequently used in medicine, food, chemistry, and cosmetics industries. Polysaccharide, total phenolic, and militarine are the main bioactive components of B. striata that have been widely used for the treatment of hematemesis, hemoptysis, and traumatic bleeding due to the efficacy of arresting bleeding with astringent action. As the yield and quality of medicinal materials are closely related to the harvest time, it is of great significance to choose the optimal harvest time of B. striata. In the present study, effects of four different harvest times of 2-year-old B. striata were compared based on their morphological characteristics and bioactive compounds contents. The results showed that the fresh weight and drying rate of B. striata showed non-significant difference among four different harvest times. However, the content of B. striata polysaccharide (BSP) was firstly decreased and then gradually stabilized with the delaying of the harvest time. The contents of total phenolic and militarine in the B. striata harvested on Sep. 23 were the highest. Under the comprehensive consideration of B. striata quality and yield, the results indicated that it is more reasonable to harvest B. striata in late September.

Calcium ions (Ca²⁺) are absorbed from the soil by the root cells before being distributed throughout the plant. The transport of Ca²⁺ to aboveground parts relies on the movement of xylem, which is influenced by the transpiration rate of individual organs. The final distribution of Ca²⁺ in tissues and cells depends on the effective function of channels and transporters that facilitate Ca²⁺ movement through plasma and specific intracellular membranes. Local fluctuations in free Ca²⁺ concentrations serve as a mechanism to elicit cellular responses, characterized by distinct calcium signatures, or to enable long-distance signaling in a cell-to-cell network. The specificity of individual Ca²⁺ transport proteins is primarily determined through studies in plants with induced changes in the expression of these proteins. Concurrently, it is recognized that plant cells contain significant reserves of Ca²⁺ both in the labile and in the permanently bound states, which influences various aspects such as biomechanical properties or the defensive capabilities of the cells. The diverse roles of Ca²⁺ in plant cells highlight the importance of a thorough understanding of Ca²⁺ metabolism.

Ovate family proteins (OFPs) are plant-specific, transcriptional repressors characterized by an OVATE domain. The OFP family has been analyzed only from a handful and functionally characterized from even fewer species. There is a gap in cataloging the complete compendium of OFP family across Gramineae although the complete genome sequence for several species are now available. In the present study, we identified and cataloged homologs of OFPs across ten Gramineae members to analyze gene and protein structure and properties, evolutionary relationship, expression pattern, and predict interacting partners. A positive correlation was found between genome-size and OFP family size, with Triticum genome harboring the maximum number; most of the Gramineae OFPs are intronless. Comparative analysis revealed variation in gene sizes, physico-chemical properties of proteins, and their structures including motifs. Phylogenetic reconstruction reflected homolog-based clustering. Expression analysis in Oryza revealed spatio-temporal variation with maximum expression in reproductive tissues. Prediction of interactome showed homeobox domain containing proteins as major interacting partners. The study thus form foundation for future functional analysis of role of OFPs in regulating economically important traits.

Pea is the third most widely grown leguminous vegetable crop globally. The crop is fairly easy to grow but is salt and drought-sensitive, limiting its yield. This study aimed to explore the morphological and biochemical responses of peas under salt stress and water-deficit stress. Three pea varieties (Climax, Green grass, Meteor) were subjected to different levels [5.4 mM (Control), 50 mM, 75 mM, and 100 mM of NaCl] of salt stress. The water-deficit stress was administered by watering 100%, 75%, and 50% of field capacity. Morphological parameters showed a significant reduction under salt and water-deficit stresses in all three varieties. The highest relative water content under various levels of both stresses was 38.3% which was significantly lower than the control treatment. Chlorophyll content index (CCI) declined significantly in all three varieties, however, Climax exhibited a noteworthy CCI of 43.7 at 100 mM salt treatment, significantly higher than Green grass (25.9 CCI) and Meteor (35.9 CCI) at the same treatment. Significant accumulation of proline content was observed under both stresses, where 100 g of fresh weight of Climax showed proline content as 0.043 mg against 100 mM salt and 0.040 mg against 50% water-deficit treatments. Similar trends were recorded for water-deficit stress, indicating a shared response to both stress types. These findings provide insights into the effects of salt and water-deficit stress on pea crops, specifically focusing on the role of proline. The insights gained may aid in developing strategies to mitigate these stresses for enhanced pea crop productivity.

Many phenolics are known to possess allelopathic activity, but the allelopathic effect of pyrogallol has not been previously reported. Here, the present experiment was conducted to investigate the effects of commercially obtained pyrogallol at different concentrations on the seed germination and seedling growth of L. perenne. The results showed that (1) Pyrogallol treatment inhibited L. perenne seed germination, as evidenced by a decrease in the final germination rate and a delay in germination peaks. (2) Pyrogallol treatment reduced L. perenne plumule length, radicle length, fine root length, and fine root surface area, higher pyrogallol concentrations reduced the proportion of fine roots. (3) Higher concentrations (2.00 g/L) of pyrogallol resulted in decreased protein content and increased membrane lipid peroxidation. (4) Spraying pyrogallol inhibited the growth of L. perenne seedlings, as manifested by a decrease in plant height and biomass. Overall, our findings indicate that pyrogallol is one of the allelochemicals present in aqueous extracts of K. integrifoliola leaves that inhibits the seed germination and seedling growth of L. perenne.

Cucumber is an important vegetable crop that suffers from significant yield loss because of sub-optimal temperatures during the growing season. High temperature affects the plant's health and reduces the quality and quantity of the final harvest. Huge diversity in terms of different economically important traits, including wide temperature adaptation, is recorded in indigenous cucumber germplasm because of its Indian origin. It is necessary to identify the key traits and genotypes with the contrasting response from a large set of germplasm associated with heat stress response for understanding the physio-biochemical and molecular network associated with heat tolerance. A set of 123 germplasm was evaluated in a growth chamber with temperature stress treatment (40 °C/35 °C) for two subsequent seasons. Besides, 10 selected genotypes based on their response in the seedling stage were grown under natural field conditions with high temperatures to validate the physio-biochemical response in the seedling stage and yield parameters in the reproductive stage. Among the different parameters, slow degradation of chlorophyll, higher anti-oxidant enzyme activity, higher membrane stability index, and higher canopy temperature depression were identified as key traits explaining the heat stress response in cucumbers. Besides, the photosynthetic activities of the tolerant genotypes at the reproductive stage were also higher under field conditions, resulting in higher economic yield. Heat tolerance index was developed for 123 genotypes for seven physiological traits recorded in the present study. The optimised screening technique in the seedling stage and their validation for yield response under natural field facilitated the evaluation of a large number of genotypes for use in breeding for heat stress tolerance in cucumbers. Besides, the identified germplasm, WBC-13, DGC-103 and DARL-106 with effective heat stress tolerance will be instrumental in understanding the molecular basis of heat tolerance and designing climate-smart cucumber cultivars.