Morphological and gene expression analysis under cool temperature conditions in rice anther development

Area of Science:

• Plant Science
• Agricultural Science
• Molecular Biology

Background:

• Cool temperatures induce pollen sterility in rice, significantly affecting crop yield.
• Rice cultivars exhibit varying tolerance to cool temperature stress, posing agricultural challenges.
• Understanding the mechanisms of pollen development under stress is crucial for improving rice production.

Purpose of the Study:

• To investigate the morphological and gene expression differences in rice anther development under cool temperature stress.
• To identify the role of tapetum degeneration in cool temperature-induced pollen sterility.
• To discover genes associated with cool temperature stress response in rice.

Main Methods:

• Comparative analysis of two rice cultivars (Hitomebore and Sasanishiki) with differing cool temperature tolerance.
• Morphological examination of anther development using transverse sections under cool conditions (19°C).
• Gene expression profiling of anthers to identify differentially expressed genes between cultivars.

Main Results:

• Hitomebore (high tolerance) showed 87.3% seed fertility, while Sasanishiki (low tolerance) had 41.7% under cool stress.
• Tapetum degeneration occurred later in Hitomebore anthers, completing by the mature stage.
• In Sasanishiki, tapetum degradation was delayed, with the tapetum remaining intact at the mature stage.
• 356 differentially expressed genes were identified between the two cultivars under cool temperatures.

Conclusions:

• Tapetum degeneration is critical for normal pollen development and is strongly correlated with cool temperature tolerance in rice.
• The identified genes provide insights into the molecular mechanisms underlying cool temperature stress response in rice pollen.
• This study highlights potential targets for breeding rice varieties with enhanced cool temperature tolerance.