SlHB8 Is a Novel Factor in Enhancing Cold Resistance in Tomato Anthers by Modulating Tapetal Cell Death

Area of Science:

• Plant Molecular Biology
• Plant Physiology
• Agricultural Science

Background:

• Tomato plants are sensitive to cold, impacting reproductive development and pollen viability.
• Tapetal programmed cell death (PCD) is crucial for pollen development but susceptible to cold stress.
• Understanding cold stress response in anthers is key for improving cold-resistant tomato varieties.

Purpose of the Study:

• Investigate the role of SlHB8 in tomato anther cold tolerance.
• Elucidate the molecular mechanism by which SlHB8 regulates tapetal PCD under cold stress.
• Identify potential targets and interactions of SlHB8 in the cold response pathway.

Main Methods:

• Gene expression analysis of SlHB8 under cold stress.
• CRISPR/Cas9 gene editing to create SlHB8-knockout mutants.
• Promoter binding assays and protein interaction studies.

Main Results:

• SlHB8 expression is induced by low temperatures in the tomato tapetum.
• SlHB8-knockout mutants show enhanced pollen cold tolerance.
• SlHB8 directly upregulates SlDYT1 and SlMYB80 expression by binding to their promoters.
• SlHB8 interacts with SlTDF1 and SlMYB80, potentially regulating tapetal PCD at the protein level.

Conclusions:

• SlHB8 is a critical regulator of cold tolerance in tomato anthers.
• SlHB8 acts upstream of the DYT1-TDF1-AMS-MYB80 module to control tapetal PCD.
• This study reveals a novel molecular mechanism for plant adaptation to temperature fluctuations.