Relative Telomere Length and Telomerase Reverse Transcriptase (TERT) Expression Are Associated with Age in Almond (Prunus dulcis [Mill.] D.A.Webb)

Abstract

While all organisms age, our understanding of how aging occurs varies among species. The aging process in perennial plants is not well-defined, yet can have implications on production and yield of valuable fruit and nut crops. Almond exhibits an age-related disorder known as non-infectious bud failure (BF) that affects vegetative bud development, indirectly affecting kernel yield. This species and disorder present an opportunity to address aging in a commercially relevant and vegetatively propagated perennial crop. The hypothesis tested in this study was that relative telomere length and/or telomerase reverse transcriptase (TERT) expression can serve as biomarkers of aging in almond. Relative telomere lengths and expression of TERT, a subunit of the enzyme telomerase, were measured via qPCR methods using bud and leaf samples collected from distinct age cohorts over a two-year period. Results from this work show a marginal but significant association between both relative telomere length and TERT expression, and age, suggesting that as almonds age, telomeres shorten and TERT expression decreases. This work provides information on potential biomarkers of perennial plant aging, contributing to our knowledge of this process. In addition, these results provide opportunities to address BF in almond breeding and nursery propagation.

Identification of Putative Markers of Non-infectious Bud Failure in Almond [Prunus dulcis (Mill.) D.A. Webb] Through Genome Wide DNA Methylation Profiling and Gene Expression Analysis in an Almond × Peach Hybrid Population

“…The exhibition of NBF became a serious threat to the almond industry beginning in the 1940s when the promising and popular cultivar ‘Jordanolo’ began to exhibit the disorder and was subsequently abandoned ( Wilson, 1950 , 1952 ; Wilson and Schein, 1956 ). This pattern later repeated in the cultivar ‘Carmel,’ which was widely used until the early 2000s when widespread NBF-exhibition among clones led to its rapid abandonment ( Kester et al, 2004 ; California Department of Food and Agriculture, 2020 ; D’Amico Willman, 2021 ). This disorder has also been observed in almond growing regions outside the United States, including in Australia, Spain, and Iran and is known to affect several cultivars of almond, including ‘Nonpareil,’ and ‘Mission.’ Due to its unknown etiology, irreversibility, and the current lack of screening methods, NBF is a threat to both current cultivars as well as any future almond breeding and production efforts ( Kester and Jones, 1970 ).…”

Leveraging whole‐genome sequencing to estimate telomere length in plants

“…qPCR is widely used in telomere studies as it requires small quantities of DNA (20 ng/individual), provides scalability for high‐throughput assessments and produces results in a shorter amount of time than TRF (A et al., 2022; Heidinger et al., 2021; Lynn et al., 2022; Morinha et al., 2020b). However, the adoption of qPCR across plant systems has been limited (but see A et al., 2022 and D'amico‐Willman et al., 2021). Recent advances in whole genome sequencing (WGS) and new bioinformatic tools are now enabling estimation of telomere length using WGS.…”