Elicitor Specific Mechanisms of Defence Priming in Oak Seedlings Against Powdery Mildew

Area of Science:

• Plant Pathology
• Plant Biochemistry
• Molecular Biology

Background:

• Defence priming enhances plant responses to subsequent stress.
• Chemical elicitors like salicylic acid (SA), jasmonic acid (JA), and β-aminobutyric acid (BABA) can induce priming.
• Oak's response to chemical-induced priming against powdery mildew (PM) remained unexplored.

Purpose of the Study:

• To characterize SA-, JA-, and BABA-induced defence priming in oak seedlings against powdery mildew (PM).
• To identify unique molecular and metabolic responses associated with each elicitor.
• To elucidate the mode of action and potential crosstalk between priming pathways.

Main Methods:

• Oak seedlings were treated with SA, JA, and BABA.
• Resistance against Erysiphe alphitoides (PM) was assessed.
• Untargeted transcriptome and metabolome analyses were performed.
• Enrichment and omics integration analyses were conducted.

Main Results:

• BABA and SA enhanced resistance by priming callose deposition and SA-dependent gene expression, respectively.
• JA showed no significant effects on resistance.
• Unique genes and metabolites were identified for BABA, SA, and JA priming.
• A similar mode of action between BABA and JA was observed, with no crosstalk between SA and JA pathways.
• BABA priming was linked to alkaloid, lignan, phenylpropanoid, and indolitic compound biosynthesis, involving ubiquitination and protein degradation.

Conclusions:

• Chemical-induced defence priming exists in oak seedlings.
• Specific molecular markers associated with SA, JA, and BABA elicitors were identified.
• BABA-induced priming involves distinct metabolic pathways and protein regulation mechanisms.