Articles
Targeted genome editing and transcriptomic analysis reveal MDHAR’s role in ascorbic acid recycling networks in lettuce
Article number
1454_6
Pages
41 – 48
Language
English
Abstract
Ascorbic acid (AsA) is an essential antioxidant and nutrient in plants, helping to regulate reactive oxygen species (ROS) levels and cellular redox balance.
The AsA recycling pathway is critical for maintaining a balanced AsA ratio in plants, and monodehydroascorbate reductase (MDHAR) is known to be important for converting monodehydroascorbate (MDHA) back into AsA. However, recent findings imply a broader role for MDHAR in plants.
In this work, we focused on the MDHAR gene family in Lactuca sativa with the aim of shedding light on the functions of these genes.
Four MDHAR paralogs were edited using the CRISPR/Cas9 technique.
Despite mutations, AsA content showed no significant alterations, except for mutant LsMDHAR3 in 14-day-old plants, whereas differences in the expression of MDHAR genes were found in 14- and 28-day-old mutants compared to wild type.
With the aim of investigating possible compensatory mechanisms related to MDHAR gene mutations, transcriptomics analyses have been carried out.
Transcriptomic results showed that each edited LsMDHAR differentially regulated the expression of specific genes involved in AsA biosynthesis, as well as several genes related to phenylpropanoids, hormones, cell wall integrity, and abiotic stress, suggesting a broader involvement of the MDHAR gene family.
Furthermore, several transcription factors were found to be differentially expressed in all mdhar1-4 mutants.
Finally, a weighted gene co-expression network analysis (WGCNA) revealed a gene network linking the Lsmdhar3 mutant to genes involved in sugar metabolism, responses to abiotic stress, light, and ethylene signaling, and hydrogen peroxide detoxification.
These results identify promising candidate genes related to MDHAR gene expression that may play a role in the regulation of AsA recycling, as well as in other related pathways, laying the foundation for future research aimed at improving our understanding of the complex gene regulation related to AsA.
The AsA recycling pathway is critical for maintaining a balanced AsA ratio in plants, and monodehydroascorbate reductase (MDHAR) is known to be important for converting monodehydroascorbate (MDHA) back into AsA. However, recent findings imply a broader role for MDHAR in plants.
In this work, we focused on the MDHAR gene family in Lactuca sativa with the aim of shedding light on the functions of these genes.
Four MDHAR paralogs were edited using the CRISPR/Cas9 technique.
Despite mutations, AsA content showed no significant alterations, except for mutant LsMDHAR3 in 14-day-old plants, whereas differences in the expression of MDHAR genes were found in 14- and 28-day-old mutants compared to wild type.
With the aim of investigating possible compensatory mechanisms related to MDHAR gene mutations, transcriptomics analyses have been carried out.
Transcriptomic results showed that each edited LsMDHAR differentially regulated the expression of specific genes involved in AsA biosynthesis, as well as several genes related to phenylpropanoids, hormones, cell wall integrity, and abiotic stress, suggesting a broader involvement of the MDHAR gene family.
Furthermore, several transcription factors were found to be differentially expressed in all mdhar1-4 mutants.
Finally, a weighted gene co-expression network analysis (WGCNA) revealed a gene network linking the Lsmdhar3 mutant to genes involved in sugar metabolism, responses to abiotic stress, light, and ethylene signaling, and hydrogen peroxide detoxification.
These results identify promising candidate genes related to MDHAR gene expression that may play a role in the regulation of AsA recycling, as well as in other related pathways, laying the foundation for future research aimed at improving our understanding of the complex gene regulation related to AsA.
Authors
T. Giordani, U. Rogo, S. Simoni, A. Viviani, A. Vangelisti, C. Pugliesi, M. Fambrini, A. Cavallini, L. Natali, R. Michelmore
Keywords
Lactuca sativa, CRISPR/Cas9, Vitamin C, RNA-seq
Groups involved
- Division Plant Genetic Resources, Breeding and Biotechnology
- Working Group Genetic Transformation and Gene Editing
- Working Group Horticultural Biotechnology and Breeding
- Division Ornamental Plants
- Division Vegetables, Roots and Tubers
- Division Temperate Tree Fruits
- Division Vine and Berry Fruits
- Division Horticulture for Development
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