Comparative Analysis of Italian Lettuce (Lactuca sativa L. var. ramose) Transcriptome Profiles Reveals the Molecular Mechanism on Exogenous Melatonin Preventing Cadmium Toxicity

Abstract

Cadmium (Cd) accumulation in lettuce causes a large amount of yield loss during industry. Although many studies report that exogenous melatonin helps to alleviate the Cd stress of lettuce, the molecular mechanism for how plant tissue responds to Cd treatment is unclear. Herein, we applied both PacBio and Illumina techniques for Italian lettuce under different designed treatments of Cd and melatonin, aiming to reveal the potential molecular pathway of the response to Cd stress as well as the how the pre-application of exogenous melatonin affect this process. This result reveals that the root has the biggest expression pattern shift and is a more essential tissue to respond to both Cd and melatonin treatments than leaves. We reveal the molecular background of the Cd stress response in prospects of antioxidant and hormone signal transduction pathways, and we found that their functions are diverged and specifically expressed in tissues. We also found that candidate genes related to melatonin detoxify during Cd stress. Our study sheds new light for future research on how melatonin improves the cadmium resistance of lettuce and also provide valuable data for lettuce breeding.

Cadmium toxicity in medicinal plants: An overview of the tolerance strategies, biotechnological and omics approaches to alleviate metal stress

“…ramose using PacBio and Illumina techniques reveal the potential molecular pathway (antioxidant and hormone signal transduction) under Cd stress with and without pre-application of melatonin. The genes involved in Cd detoxification on melatonin application are identified ( Yu et al., 2022 ). The transcriptomic study conducted in two different cultivars of Brasica rapa var chinensis (Baiyewuyueman and Kuishan’aijiaoheiye) identified 797 ROS-related proteins and 1167 transcription factors encoding unigenes.…”