BMC Plant Biology最新文献

Leaf litter decomposition is a key ecological process that strongly regulates carbon sequestration and nutrient cycling in forests. While the effects of climate and initial litter nutrient chemistry on mass loss are well established, the dynamics of multiple nutrients in decomposing leaf litter, particularly those beyond nitrogen (N) and phosphorus (P), and their downstream effects on subsequent mass loss and nutrient release remain insufficiently understood. We conducted a two-year litterbag decomposition experiment using litter from seven tree species in a mixed evergreen and deciduous broad-leaved forest along an altitudinal gradient (800-1800 m a.s.l.) in subtropical China. Alongside concurrent temporal high-resolution microclimatic data, we followed changes in concentrations of multiple litter nutrients, including potassium (K), calcium (Ca), and magnesium (Mg). Despite initial variation in litter nutrient concentrations and climatic conditions, nutrient concentrations in decomposing litter generally converged over time, except for the dissimilar P and Ca at later decomposition stages. Initial nutrients, particularly P, Ca, and Mg concentrations, displayed modest but consistent effects on nutrient concentrations in decomposing litter. Most importantly, air temperature and nutrient concentrations in the decomposing litter influenced subsequent mass loss and nutrient release in distinct ways. By incorporating multiple nutrients to link nutrient dynamics in decomposing litter to the subsequent decomposition process, our study provides an integrative framework to enhance process-based predictions of nutrient and carbon cycling in forests.

Background: Lentil (Lens culinaris Medik.) is a widely cultivated food legume that is vulnerable to a variety of abiotic stressors, which can impair its growth and development and ultimately reduce yields. Some genes that confer resistance to abiotic stressors have already been identified and characterized. The GRAS gene family comprises transcriptional factors that play diverse roles in plant growth, development, and abiotic stress tolerance. Despite extensive studies in other crops, the GRAS gene family has not been characterized in lentil.

Results: This study identified 50 members of the GRAS gene family in lentils, distributed across seven chromosomes and classified into nine distinct subfamilies. Additionally, 13 duplication events were identified, comprising two tandem gene pairs and 11 segmental gene pairs. Synteny analysis discovered that segmental duplication predominated over tandem duplication among the GRAS genes. Based on RNA-Seq data, 10 genes exhibiting higher expression levels across various lentil plant tissues and developmental stages were selected for RT-qPCR analysis to validate these genes. Ten LcGRAS genes from five subfamilies - DELLA (LcGRAS34), PAT1 (LcGRAS01, LcGRAS02, LcGRAS04, LcGRAS18, LcGRAS11), LISCL (LcGRAS41, LcGRAS25), SCR (LcGRAS31), and HAM (LcGRAS40) - exhibited a significant response to abiotic stresses such as chromium, salt, and drought, as demonstrated by qRT-PCR analysis. It was hypothesized that members of the LcGRAS family play a crucial role in stress tolerance, as the expression of LcGRAS04, LcGRAS11, and LcGRAS25 genes from the PAT1 and LISCL subfamilies was significantly up-regulated at specific time points during the treatment period.

Conclusions: In addition to providing valuable insights into the evolutionary dynamics of the LcGRAS gene family, our research lays the groundwork for future studies on the functional activities of GRAS genes in lentils.

Yunnan is the primary coffee-producing region in China. With the changing consumption habits of younger consumers, the coffee industry has experienced rapid growth, and enhancing both quality and yield has become a major focus of research. However, crop growth models are predominantly applied to the simulation of annual grain crops. To date, there has been no reported research on the development of growth models specifically for Arabica coffee in Yunnan.This study is based on the coffee growth model initially assessed and calibrated using long-term experimental sites in Costa Rica and Nicaragua in Central America (Ovalle-Rivera O. et al. Agrofor. Syst. 94:2033-2051, 2020), and has been locally calibrated to construct a growth model for Arabica coffee in Yunnan. The main tasks are as follows: Focusing on the key coffee-growing regions in Yunnan, data on local climate, soil, phenology, management practices, and yield were collected. The study explored the calibration of model parameters using Bayesian optimization, gradient descent, and particle swarm optimization algorithms. By comparing two indicators-root mean square error (RMSE) and mean absolute error (MAE)-it was determined that particle swarm optimization produced the best results under Yunnan's ecological and climatic conditions, and thus, this algorithm was used to construct the Yunnan Arabica coffee growth model. Furthermore, simulations were conducted to examine the effects of varying fertilization amounts, shading practices, shading intensities, altitudes, and weather conditions on coffee growth. The study discusses the impact of these factors on the growth and yield of Yunnan Arabica coffee, providing scientific evidence for optimizing cultivation management strategies. The results indicate that moderate fertilization and shading can significantly improve coffee yield, although both factors have a "saturation point." Within a specific range of total fertilizer application, the impact of single application rates on final yield is not significant. This suggests that when formulating a scientifically sound fertilization strategy, the total nitrogen fertilizer application should be optimized first. Among the major production areas, the climate conditions in the Pu'er region are the most ideal, while other regions require tailored management measures. In summary, this research successfully constructed the Yunnan Arabica coffee growth model and simulated its performance under various conditions, revealing potential response trends of coffee to environmental changes. It provides theoretical support for the cultivation management and sustainable development of the Arabica coffee industry in Yunnan.

Heavy metal contamination and soil salinity pose significant threats to safe and sustainable vegetable production, particularly for sensitive crops such as lettuce. These combined stresses hinder nutrient uptake, accelerate toxicity, and underscore the need for effective soil amendments that can mitigate multi-stress conditions. However, the potential of low-cost, hazelnut husk-derived biochar to alleviate simultaneous cadmium (Cd) and salinity stress in lettuce remains poorly understood. This study evaluated the effects of biochar applications on lettuce (Lactuca sativa L.) grown under varying cadmium (Cd) concentrations and salt stress conditions. A greenhouse experiment was conducted using a factorial design with four levels of biochar (0, 0.5, 1, and 2%), four Cd treatments (0, 0.5, 1, and 2 mg kg⁻¹), and two salinity regimes (0 and 75 mM NaCl), with three replicates per treatment. Plant growth, yield, and the concentrations of macro-nutrients phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na), and micro-nutrients iron (Fe), copper (Cu), manganese (Mn), and boron (B), as well as Cd, were determined. Results showed that biochar significantly increased shoot biomass, improved nutrient concentrations, and reduced Cd accumulation in lettuce shoots. Under non-saline conditions, the highest biochar dose (2%) reduced shoot Cd concentrations by approximately 30-50% across Cd levels and increased shoot biomass by about 40-50% compared with the non-amended control. Under saline conditions, biochar still decreased shoot Cd concentrations by around 25-30% and increased shoot dry weight by up to nearly 60%. Across Cd and salinity levels, biochar markedly reduced shoot Na concentrations (by almost 90%) and enhanced K⁺, Mn, and B concentrations; under salt stress, Zn increased by approximately 40%. Principal Component Analysis (PCA) revealed that PC1 primarily reflected gradients associated with the effects of biochar and Cd on nutrient and Cd profiles, whereas PC2 captured variability driven by salinity. Overall, these findings demonstrate that hazelnut husk-derived biochar is an effective and low-cost soil amendment that can improve nutrient status, reduce Cd bioavailability, and mitigate salinity-induced ionic imbalances, offering a practical strategy for enhancing lettuce production in Cd-contaminated and saline soils.

Background: Lower soil quality is one of the biggest challenges that limit farming systems under arid regions. However, little is known about the use of organic components and their synergistic effects to restore arid soil quality. Here, we evaluated the impacts of peat moss, biochar, and gypsum on the seed germination, seedlings growth and nodulation of Acacia tortilis considering their separated and combined effects under natural conditions.

Method: Acacia tortilis seed germination, seedlings growth and nodulation were exposed to the following treatments: (a) gypsum alone, (b) gypsum + peat moss, (c) gypsum + biochar, (d) gypsum + peat moss + biochar with three levels of gypsum applications including 0, 5 and 10%, and one rate of date palm biochar (2%).

Results: Based on the findings, photosynthetic photon flux density (PPFD) values (1255.69 µmol m^- 2 s^- 1) and temperatures (40.04 °C) were greater in the noontime, while relative humidity values (29.68%) were lower. Soil treated with peat moss alone had a higher pH (7.43), while electrical conductivity (EC; 2.36 mS cm^- 1), and water holding capacity (WHC; 64.33%) were greater in soils treated with all three agricultural components. The amounts of potassium, magnesium, manganese, iron, lead, chromium, cobalt, and copper were less in the soil treated with the three agricultural materials. Germination percentage (95.55%), seed vigor index (9.67), shoot length (12.33 cm), leaves number/plant (10.66), shoot dry weight (0.1 g), root dry weight (0.03 g), chlorophyll a (0.76 mg g^- 1), chlorophyll b (0.24 mg g^- 1), total carotenoids (0.16 mg g^- 1), ash (5.71%), nodules number/plant (7), and nodule length (6.66 mm) were higher in the soil treated with the three mixtures whereas, root length was highest (16.66 cm) in the mixture of gypsum and biochar.

Conclusion: The results of this study suggest that emphasizing these agricultural materials while farming could potentially and positively optimize arid soil quality and then help in water and nutrients retention.

Agent-assisted phytoextraction is an attractive strategy to remove heavy metals from soil. However, there is a lack of effective and sustainable agents. In this study, 10 types of plant extracts were extracted and selected to combined with N, N-bis (carboxymethyl) glutamic acid (GLDA) to prepare the compound activating agent, and its effectiveness and potential risk in enhancing Cd phytoextraction by Lantana camara L. (L. camara) were evaluated. Among the 10 plant extracts, Houttuynia cordata Thunb. extract (HC) showed the highest Cd extraction ability (24.58%). When combined with GLDA (0.9%) in a 1:1 volume ratio, the compound activating agent removed Cd most effectively (79.23%) from soil. In the pot experiment, this agent increased the shoot biomass, Cd concentration, and accumulation in L. camara by 17.45%, 71.43%, and 100.42%, respectively, compared with the Cd treatment. Additionally, soil DOC (+ 17.47%) and available Cd (+ 34.05%) were significantly increased vs. Cd treatment. Acid soluble Cd increased significantly, while the reducible and oxidizable Cd fractions decreased. In the soil column experiment, leached Cd from soils treated with this agent treatment was significantly lower than from EDTA treated soils. Collectively, the compound activating agent enhanced Cd phytoextraction by L. camara through its activation effect and increased soil DOC, which promoted the conversion of oxidizable/reducible Cd to acid soluble Cd and mobilized soil Cd for plant uptake. Thus, the HC extract combined with GLDA compound activating agent is a promising enhancer for Cd phytoextraction.

Salinity is a major abiotic stressor limiting the productivity of legume crops, especially in arid and semi-arid regions. Bambara groundnut (Vigna subterranea L.), a climate-resilient legume, holds great promise for food and nutritional security but remains underutilized and poorly studied under saline conditions. This study investigated the impact of magnesium nitrate Mg(NO₃)₂ seed priming on the morphological, physiological, and biochemical responses of two Bambara groundnut genotypes (BGN-14 and BGN-25) under salinity stress. Seeds were primed with 0.03% Mg(NO₃)₂ and exposed to 200 mM NaCl, with treatments including "control", "primed", "salt-stressed", and "primed + salt" conditions. The results revealed that salinity significantly impaired plant growth, reduced relative water content (RWC), chlorophyll and carotenoid levels, and increased oxidative damage through superoxide radical accumulation and cell death. However, Mg(NO₃)₂ priming significantly enhanced growth parameters, photosynthetic pigment concentration, water retention, and antioxidant activity, particularly in the "primed + salt" treatment. Notably, BGN-14 exhibited greater photosynthetic resilience and root-level antioxidant activity, while BGN-25 showed superior water conservation and shoot-based antioxidant responses. The study highlights nitrate priming as a low-cost, effective strategy to mitigate salinity-induced damage in Bambara groundnut, with genotype-specific mechanisms contributing to stress tolerance. The results provide a foundation for integrating Mg(NO₃)₂ seed priming into salinity management strategies aimed at improving the growth performance and stress resilience of Bambara groundnut in salt-affected agroecosystems.