ABA gene expression during kernel development in relation to pre-harvest sprouting in wheat and triticale

Area of Science:

• Plant Biology
• Agricultural Science
• Molecular Biology

Background:

• Pre-harvest sprouting (PHS) is a significant issue in cereal production, particularly during unfavorable weather conditions.
• Abscisic acid (ABA) is known to play a role in seed dormancy and could potentially enhance PHS tolerance.

Purpose of the Study:

• To investigate abscisic acid (ABA) levels and the expression of ABA biosynthesis and degradation genes during kernel development in wheat and triticale.
• To explore the potential of these genes for improving PHS tolerance in these cereal crops.

Main Methods:

• Controlled growth of PHS-tolerant and susceptible wheat and triticale varieties from flowering to harvest.
• Regular kernel harvesting for ABA quantification and RNA extraction.
• RT-qPCR analysis of ABA synthesis genes (ZEP, NCED1, NCED2) and degradation genes (CYP707A1, CYP707A2).

Main Results:

• ZEP gene expression peaked towards harvest maturity, differing from findings in Arabidopsis.
• NCED1 expression correlated with ABA levels during kernel development, while NCED2 was prominent in early development.
• CYP707A1 expression was linked to ABA degradation near harvest, and CYP707A2 correlated with ABA regulation throughout development.
• No significant differential gene expression was observed between PHS-tolerant and PHS-susceptible varieties.

Conclusions:

• While specific ABA-related genes show distinct expression patterns during wheat and triticale kernel development, these patterns did not differ between PHS-tolerant and susceptible varieties.
• The investigated ABA biosynthesis and degradation genes may not be the primary determinants of PHS tolerance in the studied wheat and triticale varieties.