Telomere length associates with regenerative capacity in Brassica napus L.

Plant cells exhibit strong pluripotency, enabling them to form dedifferentiated tissues such as callus. The formation of callus involves sustained cell division, resulting in significant consumption of telomere length. However, the involvement of telomeres and the mechanisms responsible for maintaining chromosome end integrity during callus formation remain poorly understood. In this study, we observed an accumulation of telomere length during the dedifferentiation stage, which peaked at approximately 18 days of cultivation. Subsequently, telomere length rapidly decreased concurrently with accelerated cell division and callus swelling. A comparison of materials with longer initial telomeres lengths and greater Telomerase Reverse Transcriptase (TERT) activity (e.g. J9707), and those with shorter telomeres (e.g. ZS11), revealed that longer telomere ends accumulated after 18 days of cultivation, leading to greater regeneration capacity. The difficulty in callus swelling observed in ZS11 may be attributed to insufficient telomere length accumulation in the early stages, resulting in an inability to withstand rapid cell division later on. These findings suggest a correlation between telomere length and regeneration activity. Additionally, we assessed telomere length and regenerative capacity in 14 independent B. napus lines, revealing an association between regeneration capacity and original telomere length. Our study revealed intricate dynamic changes in telomeres during callus formation, suggesting their potential role in regulating regenerative capacity. This study contributes to our understanding of telomere functions in plant regeneration and suggests a promising molecular marker for assessing rapeseed regenerative ability.