Deterioration of RNA in dry-stored seeds occurs slowly and contemporaneously with loss of viability, making RNA quality an excellent marker for changes in seed quality during long-term storage.

INDAZIFLAM: A NEW CELLULOSE BIOSYNTHESIS INHIBITING HERBICIDE PROVIDES LONG-TERM CONTROL OF INVASIVE WINTER ANNUAL GRASSESInvasive winter annual grasses such as downy brome (Bromus tectorum L.) are a threat to native ecosystems throughout the US. These invasive grasses exploit moisture and nutrients throughout the fall and early spring before native plants break dormancy. This results in decreased native species abundance and development of monotypic stands. Short-term downy brome management has been shown to be effective; however, the soil seed reserve has often been overlooked although it's the mechanism responsible for rapid re-establishment. While glyphosate, imazapic, and rimsulfuron are herbicides commonly recommended to control invasive, annual grasses, their performance is inconsistent, and they can injure desirable perennial grasses. Indaziflam is a recently registered cellulose-biosynthesis inhibiting herbicide, providing broad spectrum control of annual grass and broadleaf weeds. Indaziflam (Esplanade ® , Bayer CropScience) is a cellulose biosynthesis inhibiting (CBI) herbicide that is a unique mode of action for resistance management and has broad spectrum activity at low application rates. At

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.

Aged soybean seeds show widespread cleavage of long mRNA transcripts with no particular relationship to transcript function, consistent with extant hypotheses of aging mechanisms.