Cell Wall Invertase Inhibitor SlINVINH1 Acts as a Negative Regulator in Fruit Ripening of Tomato

Area of Science:

• Plant Biology
• Biochemistry
• Genetics

Background:

• Sugar metabolism significantly influences fruit ripening, but the underlying mechanisms remain unclear.
• Cell wall invertase (CWIN) inhibitors regulate CWIN activity via protein-protein interactions, impacting plant development and stress responses.

Purpose of the Study:

• To investigate the role of a specific tomato CWIN inhibitor, SlINVINH1, in regulating fruit ripening.
• To explore the potential of manipulating CWIN inhibitor genes for agricultural applications.

Main Methods:

• CRISPR/Cas9 gene editing was used to create knockout mutants of the SlINVINH1 gene in tomato.
• Fruit ripening characteristics, CWIN activity, sugar content, and gene expression were analyzed in wild-type and mutant tomatoes.
• Transcriptome analysis was performed to identify differentially expressed genes and enriched biological pathways.

Main Results:

• CRISPR/Cas9-mediated knockout of SlINVINH1 accelerated tomato fruit ripening, increasing CWIN activity, sugar (sucrose, glucose, fructose), and carotenoid content, while decreasing chlorophyll.
• Transcriptome analysis revealed enrichment of ripening and sugar metabolism pathways in knockout mutants.
• Expression of key ripening regulators, including SlRIN, and other invertase/inhibitor genes was altered in the CR-slinvinh1 mutants, correlating with observed physiological changes.

Conclusions:

• SlINVINH1 plays a novel role in negatively regulating tomato fruit ripening.
• Targeting CWIN inhibitor genes presents a viable genetic strategy to simultaneously enhance tomato fruit ripening and sweetness.