# Plants Distinguish Different Photoperiods to Independently Regulate Post-Flowering Vegetative Growth and Reproductive Growth

## TL;DR

Plants use different light period signals to separately control growth after flowering and seed development.

## Contribution

The study reveals how plants distinguish photoperiod signals to regulate post-flowering growth independently.

## Key findings

- Photoperiod significantly affects both vegetative and reproductive growth after flowering.
- Absolute photoperiod controls cytokinin to auxin ratio, influencing branching and siliques.
- Photosynthetic photoperiod regulates photosynthesis duration, affecting biomass and siliques.

## Abstract

The post-flowering stage is critical for plant yield and seed quality. This can be influenced by the photoperiod; however, the underlying mechanisms are not clear. Arabidopsis thaliana was selected as the experimental material to test this phenomenon. Different photoperiod treatments were implemented during the post-flowering stage to comprehensively examine the effects of photoperiod on physiological and phenotypic characteristics. This work aims to explore the photoperiod measurement mechanisms that control post-flowering growth and development. Our results showed the following: (1) During the post-flowering stage, the photoperiod had a significant impact on both vegetative and reproductive growth. (2) Photoperiod measurement mechanisms can be categorized into absolute and photosynthetic photoperiods. These mechanisms exert distinct effects. (3) Absolute photoperiod regulated the cytokinin to auxin ratio, thereby controlling the number and length of branches and the number of siliques. Extending the absolute photoperiod had a preferential promoting effect. (4) Photosynthetic photoperiod affected duration of photosynthesis. This process regulated the formation and accumulation of photosynthetic products. Consequently, it influenced the biomass and efficiency of siliques. Extending the photosynthetic photoperiod had a positive effect. This study demonstrates that plants distinguish between photoperiodic signals and energy effects to independently control post-flowering development and growth.