1. The kinetics of ageing in dry-stored seeds: a comparison of viability loss and RNA degradation in unique legacy seed collections
- Author
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Margaret B. Fleming, Lisa M. Hill, and Christina Walters
- Subjects
0106 biological sciences ,RNA Stability ,media_common.quotation_subject ,Total rna ,Kinetics ,Temperature ,Longevity ,food and beverages ,RNA ,Germination ,Original Articles ,Plant Science ,RNA integrity number ,Rna degradation ,Biology ,010603 evolutionary biology ,01 natural sciences ,Horticulture ,Ageing ,Seeds ,Soybeans ,010606 plant biology & botany ,media_common - Abstract
Background and Aims Determining seed longevity by identifying chemical changes that precede, and may be linked to, seed mortality, is an important but difficult task. The standard assessment, germination proportion, reveals seed longevity by showing that germination proportion declines, but cannot be used to predict when germination will be significantly compromised. Assessment of molecular integrity, such as RNA integrity, may be more informative about changes in seed health that precede viability loss, and has been shown to be useful in soybean. Methods A collection of seeds stored at 5 °C and 35–50 % relative humidity for 1–30 years was used to test how germination proportion and RNA integrity are affected by storage time. Similarly, a collection of seeds stored at temperatures from −12 to +32 °C for 59 years was used to manipulate ageing rate. RNA integrity was calculated using total RNA extracted from one to five seeds per sample, analysed on an Agilent Bioanalyzer. Results Decreased RNA integrity was usually observed before viability loss. Correlation of RNA integrity with storage time or storage temperature was negative and significant for most species tested. Exceptions were watermelon, for which germination proportion and storage time were poorly correlated, and tomato, which showed electropherogram anomalies that affected RNA integrity number calculation. Temperature dependencies of ageing reactions were not significantly different across species or mode of detection. The overall correlation between germination proportion and RNA integrity, across all experiments, was positive and significant. Conclusions Changes in RNA integrity when ageing is asymptomatic can be used to predict onset of viability decline. RNA integrity appears to be a metric of seed ageing that is broadly applicable across species. Time and molecular mobility of the substrate affect both the progress of seed ageing and loss of RNA integrity.
- Published
- 2018
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