Comparative transcriptome analysis reveals cadmium tolerance mechanisms in two Amaranthus varieties

Area of Science:

• Plant Biology
• Environmental Science
• Molecular Biology

Background:

• Cadmium (Cd) pollution is a major agricultural and ecological concern.
• Understanding plant Cd tolerance mechanisms is vital for developing mitigation strategies.

Purpose of the Study:

• Investigate physiological and molecular mechanisms of Cd tolerance in two Amaranthus varieties (CZ074 - tolerant, CZ081 - sensitive).

Main Methods:

• Comparative physiological analysis of growth inhibition and Cd transport.
• Comparative transcriptome analysis of roots, stems, and leaves under Cd stress.

Main Results:

• Tolerant CZ074 showed less growth inhibition and lower root-to-shoot Cd transport.
• CZ074 exhibited significantly more differentially expressed genes (DEGs), particularly in root pathways like phenylpropanoid biosynthesis and cell wall formation.
• Upregulation of key transcription factors (bZIP, NAC, WRKY) and transporters (HMA3, NRAMP, CAX) in CZ074 roots.

Conclusions:

• Amaranthus CZ074 employs an active investment strategy for Cd tolerance through comprehensive transcriptional reprogramming.
• Robust root defenses, efficient Cd translocation, and precise transcriptional regulation contribute to CZ074's tolerance.
• Identified candidate genes and mechanisms for phytoremediation and breeding Cd-tolerant crops.