ABRE-BINDING FACTOR3-WRKY DNA-BINDING PROTEIN44 module promotes salinity-induced malate accumulation in pear

Area of Science:

• Plant Physiology
• Molecular Biology
• Agricultural Science

Background:

• Malate is crucial for fruit acidity and plant stress tolerance.
• Salinity stress often induces malate accumulation in plants.
• The precise molecular pathways of salinity-induced malate accumulation are not fully understood.

Purpose of the Study:

• To investigate the molecular mechanisms underlying salinity-induced malate accumulation in pear (Pyrus spp.).
• To identify key transcription factors and genes involved in this process.

Main Methods:

• Comparative analysis of malate content in pear tissues under salinity stress.
• Genetic analysis to identify regulatory factors.
• Biochemical assays, including in-vivo and in-vitro experiments.
• Promoter analysis to identify transcription factor binding sites (W-box, G-box).

Main Results:

• Salinity treatment significantly increased malate accumulation in pear fruit, calli, and plantlets.
• The transcription factor PpWRKY44 directly activates the expression of the malate transporter gene PpALMT9.
• The transcription factor PpABF3 binds to the promoter of PpWRKY44, enhancing its expression and further promoting malate accumulation.

Conclusions:

• PpWRKY44 and PpABF3 act as positive regulators in salinity-induced malate accumulation in pears.
• This regulatory pathway involving PpWRKY44 and PpABF3 is critical for pear's response to salinity stress.
• Understanding this mechanism offers insights into improving fruit quality and stress resilience in pears.