# The leaves fall, yet the tree endures

## TL;DR

This review discusses how plants age, focusing on the roles of telomeres and epigenetics in regulating longevity and senescence.

## Contribution

The paper challenges the overemphasis on telomere length and highlights the critical role of epigenetic regulation in plant aging.

## Key findings

- Telomerase activity in meristematic tissues suggests telomere length may not be the main determinant of plant lifespan.
- Epigenetic mechanisms like DNA methylation and chromatin remodeling play a key role in regulating plant senescence.
- Integrating epigenetic and chromosomal processes offers new strategies to enhance plant resilience and longevity.

## Abstract

Aging in plants presents a paradox: while individual modules such as leaves and reproductive organs undergo senescence, the plant as a whole may display extraordinary longevity, enabled by its modular architecture and perpetually active meristems. This review explores aging and senescence in plants by challenging commonly held assumptions and integrating emerging insights from telomere biology and epigenetic regulation. We critically examine the role of telomere length as a determinant of replicative lifespan, arguing that its importance is often overstated, particularly in the context of plant systems where telomerase activity persists in meristematic tissues. In contrast, the epigenetic landscape—including DNA methylation, histone modifications, chromatin remodeling, and non-coding RNAs—plays a dynamic and increasingly appreciated role in orchestrating senescence at cellular and organ levels. We synthesize current understanding of how these chromatin-level mechanisms interact with developmental cues and environmental stresses to regulate genome stability, transcriptional reprogramming, and longevity. By integrating chromosomal and epigenetic processes, this review provides a refined conceptual framework for understanding plant aging and highlights new opportunities to enhance resilience and lifespan in crops and long-lived species through targeted manipulation of telomere maintenance and epigenetic pathways.