|Wood, Andrew - SOUTHERN ILLINOIS UNIV.|
Submitted to: Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 24, 1999
Publication Date: N/A
Interpretive Summary: The work described in this manuscript is a logical extension of my ongoing research program to understand the underlying mechanisms involved in a naturally occurring plant desiccation-tolerance system. In this report we have detailed how vegetative portions (leaves) of a desiccation-tolerant plant prepares itself for recovery upon rehydration during the drying phase by the storage of gene products. These gene products (messenger RNAs for proteins required for recovery) are stored in specialized particles in the cytoplasm of the leaf cells which protect the products from damage during drying and during the dried period. Upon rehydration the gene products are released and used to recover. Such a mechanism ensures that the plant can recover quickly from drying and minimizes the energy required to do so. This work has important consequences for future work concerning drought resistance of major crop species.
Technical Abstract: Transformation studies have established that changes in gene expression observed in vivo in response to desiccation and rehydration of the desiccation-tolerant bryophyte Tortula ruralis are regulated by alterations in the pattern of selection of messenger RNAs by the translation machinery. This selection is from a qualitatively constant mRNA pool. This report presents evidence that when drying rates are slow, mRNPs are formed in the drying gametophytes and tat a representative rehydrin mRNA is sequestered into these particles. The report further demonstrates that these mRNPs are unique to drying gametophytes and from at least four size classes after in vivo UV crosslinking. A large molecular weight protein (>100 kD) is associated these particles. This is the first report of mRNP formation in response to a vegetative water deficit in plants.