Phytoremediation Potential of Cucumber (Cucumis sativus L.) For Barium (Ba) Uptake Under a Hydroponic System

Nanobiochar-assisted phytostabilization of lead and cadmium in mustard (Brassica campestris L.) is associated with reduced metal availability and improved physiological performance.

Nanobiochar is well documented for heavy metal removal from water, but its efficacy in soil phytostabilization remains less explored. This study compared nanobiochar (NB) and rice husk powder (RH) at 50 and 100 g kg-1 for improving Pb and Cd phytostabilization in mustard (Brassica campestris L.) under pot conditions. Compared with the no-adsorbent treatment, NB at 100 g kg-1 increased shoot fresh weight by 73.2% under Pb stress and 2.02-fold under Cd stress. It also increased pod number by 46.8% under Pb and 52.5% under Cd stress, while total seeds per plant increased by 80.1% and 2.26-fold, respectively. NB enhanced chlorophyll a, total chlorophyll, carotenoids, soluble sugars, and shoot accumulation of N, P, S, Ca, and K. Importantly, NB at 100 g kg-1 increased total Pb and Cd retention in soil by 12.5% and 6.6%, respectively, while reducing available Pb and Cd by 90.3% and 81.8%, respectively. It also reduced Pb and Cd accumulation in roots and shoots and decreased BAF values for both metals. Pb TF declined, whereas Cd TF showed a metal-specific response. Overall, NB-assisted phytostabilization was associated with reduced metal availability, lower plant metal accumulation, improved nutrient acquisition, and better physiological performance.

Exogenously Applied Vanillic Acid Confers Drought Resilience in Cabbage (Brassica oleracea var. capitata L.) by Modulating Morpho-Physiological and Biochemical Responses

Growth and Photosynthetic Responses of Muskmelon (Cucumis melo L.) Seedlings to Phosphorus Availability under Hydroponic Conditions

Sinorhizobium meliloti GAU-93 Inoculation Is Associated with Reduced Drought-Induced Oxidative Damage and Enhanced Flavonoid Accumulation and Antioxidant Capacity in Alfalfa

This study investigated the effects of Sinorhizobium meliloti GAU-93 inoculation on the growth and drought responses of alfalfa (Medicago sativa L.). Alfalfa seeds were inoculated with the GAU-93 strain Sinorhizobium meliloti and subjected to four soil water content levels: 15% (severe drought), 30% (moderate drought), 45% (well-watered control), and 60% (high-moisture condition). Various growth parameters, antioxidant enzyme activities, flavonoid-related traits, and membrane lipid peroxidation were measured. Increasing drought severity reduced plant growth, fresh and dry biomass, and relative water content (RWC). GAU-93 inoculation was associated with smaller reductions in these traits across several water regimes. Inoculated plants also showed higher flavonoid contents and higher expression of several flavonoid biosynthetic genes, including CHS, DFR, F3H, and PAL. In addition, GAU-93 was associated with lower membrane lipid peroxidation and higher antioxidant enzyme activities. Overall, these findings suggest that Sinorhizobium meliloti GAU-93 may help alleviate drought-induced oxidative stress and support alfalfa growth under the tested water regimes. This study provides a basis for further evaluation of GAU-93 as a microbial strategy to improve drought tolerance in forage crops.

Germination and Growth Responses of Trifoliate Orange (Poncirus trifoliata L.) Seeds to Glycerol-Chitosan-Based Biostimulant Treatments

Trifoliate orange (Poncirus trifoliata L.), a citrus rootstock valued for its cold hardiness and resistance to broad biotic stress, produces desiccation-sensitive seeds whose successful germination requires optimized pre-sowing treatments for reliable sexual propagation. This study investigated whether chitosan-based coating systems, incorporating glycerol as a plasticizer combined with either an amino acid biostimulant (betaine-proline) or gibberellic acid (GA3), could improve germination kinetics and seedling establishment. Seeds from mature fruits were subjected to 18 treatments across Petri dish and soil bioassays. In Petri dishes, the germination percentage remained uniformly high (86.67–100%), with GA3-containing formulations promoting shoot elongation and proline-betaine combinations favoring root development. In soil, treatments primarily modulated germination kinetics: GA3 combined with chitosan (1.5–2%) increased the germination speed by approximately 3.0–3.4 times relative to the control, while 1.5% chitosan with proline-betaine and glycerol yielded the fastest germination overall. Biomass responses were strongly formulation-dependent: 2% chitosan with GA3 maximized shoot and total dry weight, whereas 2% chitosan with proline-betaine and glycerol substantially improved root dry biomass and overall seedling quality. Glycerol exerted context-dependent effects, enhancing amino acid formulations while reducing performance in GA3 mixtures. These findings support the use of optimized chitosan-based treatments as effective tools for accelerating emergence and improving seedling robustness in rootstock production.

Enhancement of Morpho‐Physiological, Physiological, and Antioxidant Capacity of Saffron (Crocus sativus L.) Under Water Deficit Using ZnO Nanoparticles and Magnesium Sulfate: Implications for Saffron Yield

ABSTRACT Water deficit stress is one of the main plant growth and productivity limitation factors. In current study, the Crocus sativus plants were exposed to three irrigation regimes (FC 100%, FC 75%, and FC 25%) combined with ZnO‐NPs (0, 25, and 50 mg L−1) and MgSO4 (0, 1.5, and 3 g L−1). Growth, flowering, physiological, and biochemical characteristics were evaluated in a split‐plot experiment based on randomized complete block design (RCBD) with three replicates during 2023–2024. The results demonstrated that severe drought stress markedly reduced leaf dry weight, flower weight, flower number, stigma dry weight, and corm production, while increasing ionic leakage, catalase activity, and proline accumulation. The combined application of ZnO‐NPs and MgSO4 improved relative water content, photosynthetic efficiency, antioxidant activity, vegetative growth, and flowering performance under full irrigation and mild water deficit (75% FC) conditions, while under severe drought (25% FC), these treatments especially ZnO‐NPs intensified plant stress. CAT activity and proline content increased considerably in response to ZnO‐NPs 50 mg L−1 × MgSO4 3 g L−1 under FC 75% and FC 25%. Application of ZnO‐NPs and MgSO4 effectively alleviated drought‐induced damages under moderate irrigation (FC 75%) and enhanced plant tolerance to water stress. Results of PCA and Cluster analysis proved that application of ZnO‐NPs at 50 mg L−1 + MgSO4 3 g L−1 provide the most balanced improvement in growth, flowering, and stress tolerance traits under mild drought stress.