Cryoprotectant-Mediated Cold Stress Mitigation in Litchi Flower Development: Transcriptomic and Metabolomic...

Area of Science:

• Plant Physiology
• Agricultural Science
• Molecular Biology

Background:

• Litchi (Litchi chinensis Sonn) is a valuable fruit crop susceptible to cold stress during flowering.
• Low temperatures negatively impact litchi fruit production and quality.

Purpose of the Study:

• To investigate the efficacy of two cryoprotectants (Bihu and Liangli) in mitigating cold stress in litchi.
• To identify genes and metabolic pathways involved in cold resistance induced by cryoprotectant treatments.
• To hypothesize the functional roles of identified genes in enhancing litchi's cold tolerance.

Main Methods:

• Whole litchi plants were treated with Bihu and Liangli solutions to protect inflorescences from temperatures below 10 °C.
• Biochemical analyses measured soluble protein, sugar, proline, antioxidant enzyme (SOD, POD, CAT), and MDA content.
• Transcriptomic analysis identified differentially expressed genes (DEGs), gene ontology, and KEGG pathways.

Main Results:

• Bihu treatment altered the expression of 1243 differentially expressed genes (DEGs) and was associated with 43 signal transduction pathway genes.
• Bihu treatment affected 422 low-temperature-sensitive differentially accumulated metabolites (DAMs), primarily in lipid metabolism, organic oxidants, and alcohol pathways.
• Bihu treatment showed potential to improve litchi traits and fruit productivity compared to Liangli and control treatments.

Conclusions:

• Bihu cryoprotectant treatment confers cold resistance in litchi by modulating gene expression and metabolite profiles.
• Identified genes and metabolic pathways, including β-alanine, polycyclic aromatic hydrocarbon, linoleic acid, and histidine metabolism, are crucial for cold tolerance.
• Further genomic research is needed to fully elucidate the cold stress response mechanisms in litchi.