FLOWERING LOCUS T Improves Cucumber Adaptation to Higher Latitudes

Area of Science:

• Plant genetics
• Crop domestication
• Molecular biology

Background:

• Flowering time is critical for crop adaptation during domestication.
• Cucumber (Cucumis sativus) originated in tropical Asia and has spread globally.
• Mechanisms of cucumber's latitudinal adaptation remain largely unknown.

Purpose of the Study:

• To identify molecular mechanisms behind cucumber's latitudinal adaptation.
• To understand the genetic basis of cucumber's geographic expansion.

Main Methods:

• Cloning of flowering time loci from distinct cucumber populations.
• Analysis of genetic structural variations upstream of FLOWERING LOCUS T (FT).
• Nucleotide diversity analysis and selective sweep detection in the FT locus region.

Main Results:

• Two large deletions upstream of FT were identified in Eurasian and East-Asian cucumber populations.
• These deletions are associated with increased FT gene expression and earlier flowering.
• The FT locus region shows signatures of a selective sweep during domestication.

Conclusions:

• Large genetic structural variations upstream of FT were selected during cucumber domestication.
• These variations facilitated cucumber's spread from tropical origins to higher latitudes.
• Understanding these genetic changes is crucial for crop improvement and adaptation strategies.