Physiological and growth responses of two wheat (Triticum aestivum L.) varieties inoculated with a new strain of Bacillus siamensis under Cadmium (Cd) stress

Abstract

Bioavailability of cadmium (Cd) metal in the soils due to scarcity of good quality water and industrial waste could be the major limiting factors negatively influencing the growth and yield of crops needs prompt solution to fulfil the requirement of food for increasing world population. In the recent time, variable range of plant growth promoting rhizobacteria (PGPR) are being used on large scale in agriculture to reduce the risk of abiotic stresses on plants and increase crop productivity. Among them, the Bacillus siamensis has a huge potential to enhance the plant tolerance against abiotic stress but limited evidences are reported about the putative role of B.s in crop plants under heavy metal stress. The current study was aimed to investigate the potential of a new metal tolerant strain of B.s on two wheat (Triticum aestivum L.) varieties (NARC-2009 and NARC-2011) grown in Cd contaminated soil at different treatments i.e Cd (0, 20, 30 and 50 ppm) and Cd (0, 20, 30 and 50 ppm) + B.s. Our results depicted that Cd stress decreased the wheat growth related attributes, biomass, and photosynthetic parameters (Chlorophyll a, b and a + b) which increased in both wheat varieties upon inoculation with B.s. Moreover, Cd stress caused significant membrane damage and negatively affected the water content, water potential, and osmotic potential of leaf. However, PGPR considerably increased the soluble sugars to reduce the Cd toxicity. Overall, the plants inoculated with B.s enhanced their tolerance index of root and shoot and found better in NARC-2009 than NARC-2011. Therefore, microorganisms efficiently increase the plant growth by reducing the metal toxicity.

Cadmium Immobilization in the Rhizosphere and Plant Cellular Detoxification: Role of Plant-Growth-Promoting Rhizobacteria as a Sustainable Solution

“…218 For instance, Bacillus subtilis, a metal-resistant bacterium, was described to slash the Cd accumulation and promote plant growth in Oryza sativa grown under Cd. 219 Again, Burkholderia sp. D54 significantly forms Fe and Mn precipitates and arrests the uptake of metals upon root surfaces of Sedum alfredii by oxidizing Fe(II) and Mn(II).…”

“…Moreover, the PGPR can modulate the metal transporter genes ( ZIP genes) that negatively influence Cd accumulation in Zea mays . For instance, Bacillus subtilis, a metal-resistant bacterium, was described to slash the Cd accumulation and promote plant growth in Oryza sativa grown under Cd . Again, Burkholderia sp.…”

Current Advances in Medicinal Plants, Plant Physiology, Eco-Agricultural Sciences and Modern Applications for Coping the Plant Stresses

“…The chemical composition and biological activity of the essential oils extracted from Thymus vulgaris were assessed at four different phases of the biological process. The inhibitory effects of the thyme volatile oils on six gram-positive and nine gram-negative bacterial strains were investigated [13,14]. The antibacterial activity of the essential oils was determined using the bio-impedance approach, and the detection time the metric used to describe and measure the antibacterial activity of the thyme oils.…”

“…The investigated oils also demonstrated to have intelligent antibacterial action by direct contact, which appeared to be more potent against gram-negative bacteria. While the majority of the strains is found to have been nearly entirely inactivated, a few species were able to restore at least 50% of their metabolic activity upon contact with the inhibitor [13,14].…”

“…Due to water constraint brought on by global warming, agricultural regions worldwide are forced to be irrigated with salty water, which increases the salt content of the soil. One of the biggest obstacles to contemporary agriculture is salinity, or the accumulation of excessive salt in the soil, which eventually inhibits and damages plant growth and development and results in plant death [14,15].…”