A collaborative research team has uncovered a new molecular switch that plays a crucial role in determining when plant leaves begin to age. This pioneering finding may prove pivotal to how we conceive and understand basic plant biology as well as how plants allocate nutrient resources. Professors Pyungok Lim, Jongchan Lee, and Minsik Kim from the Daegu Gyeongbuk Institute of Science & Technology first authored the study. Their efforts are a major leap forward for plant science.
The study focused on a particular type of RNA known as chlorella RNA. This RNA begins its life in the nucleus, eventually traveling to the chloroplasts. This particular RNA is powerful enough to actively regulate the aging process of plant leaves. It achieves this by binding to CORONATINE INSENSITIVE 1 proteins, part of the plastid-encoded RNA polymerase complex (PEP complex), which is essential for transcribing genes in chloroplasts. Next, they compared these characteristics to RNA produced in the more familiar plant, Arabidopsis. This processed form is then transported via the cytoplasm to exert its regulatory effects within the chloroplasts.
And that’s partly because the study was very multidisciplinary. It integrated high-resolution mass spectrometry with single-molecule imaging techniques to investigate the intricate mechanisms involved in leaf senescence. These ways of analyzing the data allowed researchers to reveal the protective role of chlorella RNA. And they went on to show how this RNA mediates anterograde, nucleus-to-chloroplast signaling.
Apart from its contribution to aging, the study revealed the intricate way in which ragged chloroplast resources are reallocated throughout the plant. These resources are directed to seeds, providing essential nutrients for the next generation, or sent to stems and roots to prepare for subsequent growing seasons. By this we mean a highly developed system of resource allocation that further reinforces healthy and persistent plant life.
The study uncovers regulation and patterns of chloroplast gene expression following a pattern similar to that of the model plant Arabidopsis thaliana. Given this similarity, it is exciting and important that this work can be applied to other plant species. These discoveries offer a fresh perspective on how plants carefully allocate and deallocate their limited internal resources as they mature over time.
The results of this significant study have been published with DOI: 10.1038/s41477-025-02129-z and are subject to copyright regulations. The significance of the discovery within the field of plant biology was thoroughly reported by Phys.org on October 31, 2025.