Tomato plants grown in space switched thousands of genes; Nasa study reveals how light helps replace gravity as a growth signal

A tomato plant carries thousands of genes that stay largely quiet under normal growing conditions. Send that plant into orbit, however, and a striking number of them switch on or off within weeks. New research examining 'Red Robin' tomatoes grown aboard the International Space Station has found that once gravity is taken out of the equation, plants lean on light as their main organising cue, and the colour of that light determines how the genome responds. According to the study published in BMC Plant Biology, titled ‘Stress and light spectral quality influence the transcriptome of a tomato crop on the International Space Station’, red-rich lighting kept gene activity comparatively steady during spaceflight, while blue-rich lighting drove far greater volatility across leaf and root tissue. The same plants also grew unusually extensive roots along their stems, a stress response rarely seen at this scale in ground-based tomatoes.