Physiological, transcriptomic, and metabolomic analyses uncover crucial factors enhancing cadmium stress tolerance in centipedegrass

This study analyzed the physiological, transcriptomic, and metabolomic changes in centipedegrass to elucidate the pivotal mechanisms involved in Cd tolerance. Centipedegrass exhibited a heightened capacity for Cd absorption and transportation. Moderate Cd concentrations had no significant impact on plant growth, whereas elevated Cd concentrations inhibited growth. Higher Cd levels led to decreased photosynthetic efficiency, elevated lignin, abscisic acid (ABA), and salicylic acid (SA) contents, increased activity of antioxidant enzymes, and malondialdehyde (MDA) levels. The integrated analysis of the transcriptome and metabolome revealed the potential critical roles of phenylpropanoid biosynthesis, plant hormones, and ABC transporters in Cd detoxification in centipedegrass. Overexpression of the metal transporter ATP-binding cassette B11 (EoABCB11) in Arabidopsis conferred high Cd tolerance. These findings indicate that centipedegrass possesses robust resistance and transport capabilities against Cd toxicity, potentially attributed to ABA-, SA-, and lignin-mediated positive defense responses, primarily involving enhanced antioxidant enzyme activity and cell wall reinforcement. Overall design: These pots were filled with red soil containing varying cadmium concentrations: 0 (CK), 50 (Cd50), 100 (Cd100), and 200 mg kg-1 (Cd200) (CdCl2).