Project name: Exposure of meiosis-to-microspore-stage tomato flowers to long-term mild heat results in pollen failure after mitosis.

Description: Crop reproductive success is significantly challenged by heatwaves, which are increasing in frequency globally. The main reason is reduced male fertility due to abnormal pollen development, but the mechanism behind the developmental deviation is not well understood. Here, long-term mild heat (LTMH) treatment, mimicking a heatwave, was applied to flowers or whole plants and followed up by cytological, transcriptomic and biochemical analyses. LTMH was shown to act directly on the flowers and not via a systemic effect on other plant tissue. The meiosis to early microspore stage was the most to LTMH and three to four days of LTMH exposure around this period was sufficient to significantly reduce pollen viability. Extensive cytological analysis showed that abnormalities in pollen development could first be observed after pollen mitosis I and tapetum development appeared unaffected. Transcriptomic and biochemical analyses suggested that pollen development suffers from tapetal ER stress, with a limited role for oxidative stress. These characteristics differentiate the response of developing anthers and pollen to LTMH from that to severe heat stress.Overall design: 12 samples in total, consisting of 3 sample types with 4 replicates each. Sample types: 1) control temperature (CT), 2) 1 day long-term mild heat (1D-LTMH), 3) 4 days long-term mild heat (4D-LTMH).

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: Agricultural

Last updated: 2021-07-15