Trichoderma asperellum promotes cadmium accumulation within maize seedlings

Abstract

Cadmium (Cd) is one of the most toxic heavy metal pollutants known to accumulate in the soil environment and pose a threat to public health. The tolerance of endophytic fungi isolated from Kosteletzkya virginica to cadmium was determined by the Oxford cup method. Trichoderma asperellum displayed the highest tolerance to cadmium on potato dextrose agar (PDA) medium and was selected subsequently for inoculating maize seedlings. Green fluorescein protein (GFP) labeled T. asperellum colonised in the roots of maize seedlings. Under Cd stress, the plant height, dry weight, fresh weight, root length, chlorophyll content and antioxidant enzyme activity of maize seedlings inoculated with T. asperellum were significantly higher than those of the control. T. asperellum also contributed to the up-regulated expression of some key genes in roots and leaves of maize seedlings, involving nitrogen absorption and metabolism to promote maize growth and Cd detoxification, accumulation, distribution, etc. for Cd transport to increase resistance to Cd.

Keywords

• zea mays l.
• trichoderma asperellum
• cadmium tolerance