Heavy metals in bamboo shoots from Southeastern China and risk assessment

Silicon reduces lead accumulation in Moso bamboo via immobilization and suppression of metal cation transporter genes in roots

Lead (Pb) is a hazardous element that affects the growth and development of plants, while silicon (Si) is a beneficial element for alleviating the stress caused by heavy metals, including Pb. However, the mechanisms by which Si reduces Pb accumulation in Moso bamboo (Phyllostachys edulis (Carr ·) H · de Lehaie) remain unclear. In this study, physiological assessments and transcriptome analyses were conducted to investigate the interaction between Si and Pb. Our findings showed that Si application has no significant effect on alleviating Pb-induced inhibition of root elongation and dry weight in short-term and long-term experiments, respectively. However, it did rescue leaf yellowing and reduce Pb accumulation, particularly in the shoot. Pre-treatment with Si led to a reduction in Pb uptake, translocation and accumulation, coupled with an increase in Pb fixation within the hemicellulose of the root cell wall, resulting in a lower Pb concentration in the cell sap. At the cellular level, Pb was found to be distributed in all cells of roots, and Si pretreatment did not alter Pb distribution. Additionally, Si application downregulated the expression of genes related to ABC and metal cation transporters. These findings indicate that Si reduces Pb accumulation in Moso bamboo by immobilizing Pb in the hemicellulose of root cell walls and downregulating the expression of transporter genes involved in Pb uptake and transport.

Screening and evaluation of bamboo shoots: Comparing the content of trace elements from 100 species

Hundreds of bamboo shoots have been reported to be edible, but the accumulation of trace elements and hazardous elements in bamboo shoots is poorly understood. Here, 100 bamboo species have been evaluated by screening elements including B, Fe, Mn, Cu, Zn, Cd, Pb and As in bamboo shoots using different assessment systems. Bamboo shoots displayed different morphological characteristics, and large differences were found in the concentration of elements. Most bamboo shoots were rich in Fe and Zn and low concentrations of hazardous elements, but the concentration of Cd and Pb exceeded the maximum permissible limits of tuber vegetables in some bamboo species. Different bamboo shoots were ranked differently in the four assessment systems, and the comprehensive evaluation assigned final scores to all 100 bamboo shoots. This study provides valuable recommendations for selecting high-quality bamboo shoots that are rich in trace elements nutrition while minimizing the potential for hazardous element accumulation.

Traditional utilization of bamboo in the Central Siwalik region, Nepal

Bamboo are the fastest growing perennial woody grasses that have versatile applications. Most of the local people inhabiting the riverine area of the Siwalik region of Nepal rely on bamboo products for economic benefits and medicinal uses. Our objective was to identify the diversity of bamboo species, their ethnomedicinal practices, and economic and ecological importance. Data were collected by direct observation, key informant interviews, participatory rural appraisal, inventory technique, focus group discussions, and a household survey using semi-structured and structured questionnaires. We recorded four genera and nine species of bamboo, of which eight species have been used for agriculture, five for medicine, four for construction, food, fodder, artifacts and religious purpose, three for river embankment, and two for ornamental purpose. As the local people in the study area were deprived of medical facilities, using traditional herbal medicine to cure various diseases was a common practice. The inhabitants responded that they use bamboo-based primary ethnomedicinal care even against snake and scorpion bites. Similarly, they use bamboo young culm for reducing body weight and control diabetes. The value of the informant consensus factor was found to be maximum for the bamboo against snake and scorpion bites (1.0) and minimum for weight loss (0.81). This study concludes that the traditional utilization of all kinds of bamboo in the region is vast despite their less diversity. The recorded bamboo species are used not only for food and fodder but also in preparing artifacts, soil nutrients restoration in the fallow land, construction materials for the rural people, river embankments, and religious and spiritual purposes. Therefore, if grown on a large scale, bamboo can provide sustainable benefits for the local users and ecological aspects. Bambusa tulda and Dendrocalamus strictus have a broad spectrum of pharmacological agents. Considering the multifaceted application of bamboo in the Siwalik area, it is worthwhile to encourage the local people to bamboo plantation, which would contribute to supplement their household requirements and be one of the alternative livelihood options.

Sodium Nitroprusside Improves Bamboo Resistance under Mn and Cr Toxicity with Stimulation of Antioxidants Activity, Relative Water Content, and Metal Translocation and Accumulation

Sodium nitroprusside (SNP), as a single minuscule signaling molecule, has been employed to alleviate plant stress in recent years. This approach has a beneficial effect on the biological and physiological processes of plants. As a result, an in vitro tissue culture experiment was carried out to investigate the effect of high and low levels of SNP on the amelioration of manganese (Mn) and chromium (Cr) toxicity in a one-year-old bamboo plant, namely Pleioblastus pygmaea L. Five different concentrations of SNP were utilized as a nitric oxide (NO) donor (0, 50, 80, 150, 250, and 400 µM) in four replications of 150 µM Mn and 150 µM Cr. The results revealed that while 150 µM Mn and 150 µM Cr induced an over-generation of reactive oxygen species (ROS) compounds, enhancing plant membrane injury, electrolyte leakage (EL), and oxidation in bamboo species, the varying levels of SNP significantly increased antioxidant and non-antioxidant activities, proline (Pro), glutathione (GSH), and glycine betaine (GB) content, photosynthesis, and plant growth parameters, while also reducing heavy metal accumulation and translocation in the shoot and stem. This resulted in an increase in the plant's tolerance to Mn and Cr toxicity. Hence, it is inferred that NO-induced mechanisms boosted plant resistance to toxicity by increasing antioxidant capacity, inhibiting heavy metal accumulation in the aerial part of the plant, restricting heavy metal translocation from root to leaves, and enhancing the relative water content of leaves.