# Sensitivity to Photoperiod Is a Complex Trait in Camelina sativa

## TL;DR

Camelina sativa shows varying sensitivity to day length, with complex genetic mechanisms affecting both seedlings and adult plants.

## Contribution

The study reveals that photoperiod sensitivity in Camelina sativa is a complex trait with distinct seedling and adult responses.

## Key findings

- All tested Camelina sativa accessions showed some photoperiod response.
- Seedling and adult photoperiod responses were not correlated, indicating separate mechanisms.
- Differentially expressed genes did not align with photoperiod sensitivity differences.

## Abstract

Day neutrality, or insensitivity to photoperiod (day length), is an important domestication trait in many crop species. Although the oilseed crop
C. sativa
has been cultivated since the Neolithic era, day‐neutral accessions have yet to be described. We sought to leverage genetic diversity in existing germplasms to identify
C. sativa
accessions with low photoperiod sensitivity for future engineering of this trait. To do so, we quantified variation in hypocotyl length across 161
C. sativa
accessions of 4‐day‐old seedlings grown in long‐day and short‐day conditions as a high‐throughput approximation of variation in the photoperiod response. Soil‐grown adult plants from selected accessions also showed variation in the response to day length in several traits; however, the responses in seedling and adult traits were not correlated, suggesting complex mechanistic underpinnings. Although RNA‐seq experiments of the reference accession Licalla identified several differentially regulated Arabidopsis syntelogs involved in photoperiod response and development, including COL2, FT, LHY, and WOX4, expression of these genes in the accessions did not correlate with differences in their photoperiod sensitivity. Taken together, we show that all tested accessions show some degree of photoperiod response and that this trait is likely complex, involving several and separable seedling and adult traits.