Department of Soil Science, Faculty of Agriculture and Environment, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan.
Department of Soil Science, Faculty of Agriculture and Environment, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan.
Plant Physiol Biochem. 2024 Sep;214:108955. doi: 10.1016/j.plaphy.2024.108955. Epub 2024 Jul 22.
Chromium (Cr) is a well-known environmental pollutant while less information is available on the role of Cr-resistant bacteria in the alleviation of Cr-stress in chili (Capsicum annum L.) plants. Effect of Cr-resistant bacterial strains on growth and Cr uptake by chili plants was investigated. The results revealed that Cr-stress showed a negative effect on germination, photosynthesis, and relative water content but the inoculation ameliorated the plant stress. Chromium-resistant bacterial strains enhanced the shoot and root growth (33% SL, 19.7% RL), shoot and root dry weight (35%, 32.9%), relative water content (32.25%), membrane stability index (46.52%) SPAD value (50.76%), Cr concentration in shoots and roots (19.87 and 18.52 mg kg), bioaccumulation and translocation factor (0.396 mgkg), and seedling vigor index (40.8%) of plants. Chromium-resistant bacterial strains enhanced the NPK uptake while reduced Cr uptake by plants. The morphological and biochemical examination of rhizobacterial strains (and NM28) resistant to Cr-stress revealed smooth, off-white colonies of bacteria composed of rod-shaped cells which are Gram positive in reaction while negative in catalase activity. High quantities of malic acid were produced by bacterial strains under study i.e. NM8 (926.12 μgmL) and NM28 (992.25 μgmL). These strains were identified as Bacillus cereus strain NM8 and Bacillus subtilis strain NM28 through 16S rRNA sequencing. Results showed that B. cereus strain NM28 is more effective than B. cereus strain NM8 in promoting the growth of Cr-stressed Chili that might be suitable to develop biofertilizer for sustainable production of vegetables under metal stress.
铬（Cr）是一种众所周知的环境污染物，而关于耐铬细菌在缓解辣椒（Capsicum annum L.）植物铬胁迫方面的作用的信息较少。本研究调查了耐铬细菌菌株对辣椒植物生长和铬吸收的影响。结果表明，Cr 胁迫对发芽、光合作用和相对含水量有负面影响，但接种可减轻植物胁迫。耐铬细菌菌株增强了地上部和根的生长（33% SL，19.7% RL）、地上部和根的干重（35%，32.9%）、相对含水量（32.25%）、膜稳定性指数（46.52%）、SPAD 值（50.76%）、地上部和根部的 Cr 浓度（19.87 和 18.52 mg kg）、生物积累和转运因子（0.396 mgkg）以及幼苗活力指数（40.8%）。耐铬细菌菌株增强了植物对 NPK 的吸收，同时减少了植物对 Cr 的吸收。对耐 Cr 应激的根际细菌（和 NM28）的形态和生化检查表明，细菌由杆状细胞组成，呈光滑、灰白色菌落，反应呈革兰氏阳性，而过氧化氢酶活性呈阴性。研究中的细菌菌株产生了大量的苹果酸，即 NM8（926.12 μgmL）和 NM28（992.25 μgmL）。通过 16S rRNA 测序，这些菌株被鉴定为 Bacillus cereus 菌株 NM8 和 Bacillus subtilis 菌株 NM28。结果表明，B. cereus 菌株 NM28 比 B. cereus 菌株 NM8 更有效地促进了受 Cr 胁迫的辣椒的生长，这可能适合开发生物肥料，以在金属胁迫下可持续生产蔬菜。
