# Photoperiod and Circadian Regulation in Plants: A Review of Insights from In Vitro Studies

## TL;DR

This paper reviews how in vitro studies help understand how plants use light cycles and internal clocks to adapt their growth and development.

## Contribution

The paper emphasizes the novel use of in vitro culture techniques to study photoperiod and circadian regulation in plants.

## Key findings

- In vitro systems allow precise study of how photoperiod affects plant processes like photosynthesis and flowering.
- Combining in vitro culture with photoperiod studies reveals how plants adapt to environmental changes.
- This approach can improve plant propagation and natural compound production for sustainable agriculture.

## Abstract

Plants rely on internal “biological clocks” to coordinate their growth and development with daily and seasonal changes in light, known as the photoperiod. This review explores how plant tissue culture (growing plants under controlled laboratory conditions) can help scientists better understand how light cycles influence plant rhythms and behavior. By analyzing studies from the scientific literature, the authors show that changes in photoperiod affect not only basic plant processes, such as photosynthesis and metabolism, but also important developmental events like flowering, tuber formation, and growth. The in vitro system allows researchers to study these effects with great precision, helping to reveal how plants adapt to environmental variations. The findings highlight that combining in vitro culture techniques with studies on photoperiod and circadian regulation provides powerful tools to improve plant propagation and increase the production of useful natural compounds. This knowledge can ultimately contribute to the development of more sustainable and resilient agricultural systems in the face of global climate challenges.

Plants possess several molecular mechanisms that enable them to adapt their development to environmental changes. Many plant biological processes depend on the circadian rhythm and are regulated by the internal biological clock. Predictable environmental changes, such as variations in photoperiod, can modulate circadian rhythms, allowing organisms to synchronize their biological processes with seasonal conditions. Plant tissue culture is a valuable tool for investigating and monitoring plant plasticity in response to environmental fluctuations, as well as for elucidating the biological changes that occur under these conditions. This review highlights the importance of in vitro culture as a tool to study the physiological plasticity triggered by photoperiod and its interaction with the plant biological clock. To achieve this, a descriptive analysis was conducted through a literature search in the Scopus database, followed by a bibliometric analysis to demonstrate the progress in the application of in vitro culture to studies on photoperiod and circadian regulation in plants.