6-Benzylaminopurine mediated augmentation of cadmium phytostabilization potential in Strobilanthes alternata.

This study unveiled the cadmium phytoremediation potential and its augmentation using 6-Benzylaminopurine in Strobilanthes alternata. Cadmium stress was provided by applying 250 mg/kg cadmium chloride in soil and 25 ppm of 6-BAP (25 ml) was administered to the plants as foliar spray. The results revealed high bioconcentration factor (BCF) (18.82 ± 0.54) and low translocation factor (TF) values (0.055 ± 0.002) for the plant based on which we strongly recommend S. alternata as a promising candidate for Cd phytoremediation. The phytostabilization potential of the plant was further enhanced by applying 6-BAP, which augmented its BCF to 22.09 ± 0.64 and reduced the TF to 0.038 ± 0.001. Cd toxicity caused a reduction of plant growth parameters, root volume, adaxial-abaxial stomatal indices, relative water content, tolerance index, moisture content, membrane stability index, and xylem vessel diameter in S. alternata. However, Cd + 6-BAP treated plants exhibited an increase of the same compared to Cd-treated plants. FTIR analysis of Cd + 6-BAP treated plants revealed increased deposition of hemicellulose, causing enhanced retention of Cd in the root xylem walls, which is largely responsible for increased phytostabilization of Cd. Therefore, 6-BAP application in S. alternata can be exploited to restore Cd-contaminated areas effectively.

The research paper "6-Benzylaminopurine Mediated Augmentation of Cadmium Phytostabilization Potential in Strobilanthes alternata" has established the Cd phytostabilization potential of the plant Strobilanthes alternata and also identified the role of 6-BAP in augmenting the Cd phytoremediation potential of this plant for the very first time. The physiological and anatomical changes in relation to the applied stress signals were also studied for the first time in S. alternata.

Adaptive physio-anatomical modulations and ionomics of Volkameria inermis L. in response to NaCl.

This study illustrates the salinity tolerance mechanisms in Volkameria inermis (a mangrove-associate), making it an ideal candidate for establishment in saline lands. The plant was exposed to 100, 200, 300, and 400 mM NaCl and the TI value indicates that the stress-imparting concentration was 400 mM. There was a decrease in biomass and tissue water, and a gradual increase in osmolytes like soluble sugars, proline, and free amino acids content was observed in plantlets with the increase in NaCl concentrations. Higher number of lignified cells in the vascular region of the plantlet's leaves treated with NaCl (400 mM) may influence the transport through the conducting tissues. SEM data reveals the presence of thick-walled xylem elements, an increased number of trichomes, and partially/fully closed stomata in the 400 mM NaCl-treated samples of V. inermis. In general, macro and micronutrient distribution tend to be affected in the NaCl-treated plantlets. However, Na content increased remarkably in plantlets treated with NaCl, and the highest accumulation was observed in roots (5.58-fold). Volkameria inermis can be a good option for phytodesalination in salt-affected areas since it is equipped with strong NaCl tolerance strategies and can be exploited for desalinization purpose of salt affected lands.

The phytodesalination potential of V. inermis was proved with the aid of physiochemical and anatomical studies, which was not yet revealed. The present study elucidated the level of NaCl tolerance in V. inermis and the development of associated adaptive responses.

Plant response to heavy metal stress toxicity: the role of metabolomics and other omics tools.

Metabolomic investigations offers a significant foundation for improved comprehension of the adaptability of plants to reconfigure the key metabolic pathways and their response to changing climatic conditions. Their application to ecophysiology and ecotoxicology help to assess potential risks caused by the contaminants, their modes of action and the elucidation of metabolic pathways associated with stress responses. Heavy metal stress is one of the most significant environmental hazards affecting the physiological and biochemical processes in plants. Metabolomic tools have been widely utilised in the massive characterisation of the molecular structure of plants at various stages for understanding the diverse aspects of the cellular functioning underlying heavy metal stress-responsive mechanisms. This review emphasises on the recent progressions in metabolomics in plants subjected to heavy metal stresses. Also, it discusses the possibility of facilitating effective management strategies concerning metabolites for mitigating the negative impacts of heavy metal contaminants on the growth and productivity of plants.

Revelations on photosystem II, thermoluminescence, and artificial photosynthesis: a retrospective of Govindjee from fundamentals to applications.

Photosynthesis, as one of the most important chemical reactions, has powered our planet for over four billion years on a massive scale. This review summarizes and highlights the major contributions of Govindjee from fundamentals to applications in photosynthesis. His research included primary photochemistry measurements, in the picosecond time scale, in both Photosystem I and II and electron transport leading to NADP reduction, using two light reactions. He was the first to suggest the existence of P680, the reaction center of PSII, and to prove that it was not an artefact of Chlorophyll a fluorescence. For most photobiologists, Govindjee is best known for successfully exploiting Chlorophyll a fluorescence to understand the various steps in photosynthesis as well as to predict plant productivity. His contribution in resolving the controversy on minimum number of quanta in favor of 8-12 vs 3-4, needed for the evolution of one molecule of oxygen, is a milestone in the area of photosynthesis research. Furthermore, together with Don DeVault, he is the first to provide the correct theory of thermoluminescence in photosynthetic systems. His research productivity is very high: ~ 600 published articles and total citations above 27,000 with an h-index of 82. He is a recipient of numerous awards and honors including a 2022: Lifetime Achievement Award of the International Society of Photosynthesis Research. We hope that the retrospective of Govindjee described in this work will inspire and stimulate the readers to continue probing the photosynthetic apparatuses with new discoveries and breakthroughs.

Chelate assisted phytoextraction for effective rehabilitation of heavy metal(loid)s contaminated lands.

The contamination of lands and water by heavy toxic metal(loid)s is an environmental issue that needs serious attention as it poses a major threat to public health. The persistence of heavy metals/metalloids in the environment as well as their potentially dangerous effects on organisms underpins the need to restore the areas contaminated by heavy toxic metal(loid)s. Soil restoration can be achieved through a variety of different methods. Being more cost-effective and environmentally sustainable, phytoremediation has recently replaced traditional processes like soil washing and burning. Many plants have been intensively explored to eliminate various heavy metals from polluted soils through phytoextraction, which is a commonly used phytoremediation approach. The ability of chelants to enhance phytoextraction potential has also received wide attention owing to their ability to elevate the efficiency of plants in removing heavy metal(loid)s. Chelants have been found to improve plant growth and the activity of the defense system. Several chelants, either non-biodegradable or biodegradable, have been reported to augment the phytoextraction efficiencies of various plants. The problem of the leaching of heavy metal(loid)s and secondary pollution caused by non-biodegradable chelants can be overcome by the use of biodegradable chelants to an extent. This review is a brief report focusing on recent articles on chelate-assisted phytoextraction of heavy metal (loids) As, Cd, Cu, Cr, Hg, Ni, Pb, U, and Zn.

The review "Chelate assisted phytoextraction for effective rehabilitation of heavy metal(loid)s contaminated land" elaborates on the chelated assisted phytoextraction of eight metals and one metalloids along with their effective chelants.

Physio-anatomical modifications and elemental allocation pattern in Acanthus ilicifolius L. subjected to zinc stress.

Physio-anatomical modifications and elemental distribution pattern in Acanthus ilicifolius subjected to Zn stress were analysed in this study. Survival of A. ilicifolius plants under a high concentration of ZnSO4 was compensated by the reduction in the photosynthetic efficacy. Micro and macro-elemental distribution pattern in the root tissues was significantly influenced by heavy metal exposure. Tolerance towards the excess toxic metal ions in the tissue of A. ilicifolius was aided by the modified anatomical features. Moreover, the increased deposition of Zn around the central vasculature of the root confirms the complexation of Zn2+ in the xylem vessels. Metal induced molecular level changes of root and leaf samples indicate the presence of OH, NH2, and CH3 deformation as well as C-O-H and C-O-C stretch. A prominent band corresponding to CH3 deformation, pointing hemicellulose fortification, occurs in the cell walls of the xylem, aiding in Zn localization. The phytostabilisation potential of A. ilicifolius is dependent on the coordinated responses which endow with phenotypic plasticity necessary to cope with Zn toxicity.

Phytostabilization of arsenic and associated physio-anatomical changes in Acanthus ilicifolius L.

The carcinogenic attribute of arsenic (As) has turned the world to focus more on the decontamination and declining the present level of As from the environment especially from the soil and water bodies. Phytoremediation has achieved a status of sustainable and eco-friendly approach of decontaminating pollutants, and in the present study, an attempt has been made to reveal the potential of As remediation by a halophyte plant, Acanthus ilicifolius L. Special attention has given to analyse the morphological, physiological and anatomical modulations in A. ilicifolius, developed in response to altering concentrations of Na2AsO4.7H2O (0, 70, 80 and 90 µM). Growth of A. ilicifolius under As treatments were diminished as assessed from the reduction in leaf area, root length, dry matter accumulation, and tissue water status. However, the plants exhibited a comparatively higher tolerance index (44%) even when grown in the higher concentrations of As (90 µM). Arsenic treatment induced reduction in the photochemical activities as revealed by the pigment content, chlorophyll stability index (CSI) and Chlorophyll a fluorescence parameter. Interestingly, the thickness and diameter of the xylem walls in the leaf as well as root tissues of As treated samples increased upon increasing the As concentration. The adaptive strategies exhibited by A. ilicifolius towards varying concentrations of As is the result of coordinated responses of morpho-physiological and anatomical attributes, which make the plant a promising candidate for As remediation, especially in wetlands.