Toward efficient screening systems for sunflower drought tolerance: a comparative and molecular perspective

Area of Science:

• Plant Science
• Agronomy
• Molecular Biology

Background:

• Increasing drought frequency necessitates improved drought-tolerant crop varieties.
• Efficient screening methods are crucial for breeding drought-tolerant crops, but their comparability is poorly understood.

Purpose of the Study:

• To compare the effectiveness of four different drought simulation systems for screening sunflower drought tolerance.
• To evaluate the molecular and physiological responses of sunflower under different drought stress conditions.

Main Methods:

• Comparison of two in vitro systems (liquid and solid media with polyethylene glycol) and two soil-based pot trials (greenhouse and climate chamber).
• Physiological and morphological characterization of sunflower seedlings (AB-OR-8 and DF-AB-2).
• Transcriptomic analysis (RNA-seq) and quantitative RT-PCR to assess gene expression in the ABA signaling pathway.

Main Results:

• All four systems effectively pre-screened sunflower for drought tolerance.
• Gene expression analysis revealed differential regulation of ABA signaling pathway genes under drought stress, serving as indicators of stress levels.
• The in vitro liquid system demonstrated the highest molecular resolution for drought stress.

Conclusions:

• The choice of drought screening system depends on specific experimental objectives and available resources.
• The in vitro liquid system is recommended for maximizing molecular insights into drought stress responses in sunflower breeding programs.