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United States Department of Agriculture

Agricultural Research Service

Title: ANALYSIS OF MRNA STABILITIES DURING POLLEN DEVELOPMENT AND IN BY2 CELLS

Authors
item Ylstra, Balke - USDA/UCB PGEC
item McCormick, Sheila

Submitted to: Plant Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 1, 1999
Publication Date: October 1, 1999

Interpretive Summary: RNA stability is important in post-transcriptional gene expression. However, its role during pollen development has not been studied in detail. We determined mRNA stabilities of 12 pollen-expressed genes. Our results show that many pollen-expressed mRNAs are indeed long-lived but that at least some mRNAs undergo decay during pollen maturation. Thus, there is no overall cytoplasmic condition in pollen that stabilizes mRNAs and specific mRNA turnover mechanisms must exist. Furthermore, our results shows that mRNA stability can be tissue-specific.

Technical Abstract: RNA stability is important in post-transcriptional gene expression. However, its role during plant male gametophyte development has not been studied in detail, probably because of technical difficulties and because earlier work suggested that, in general, mRNAs expressed during late pollen development would be stable. We determined mRNA stabilities of 12 pollen-expressed genes. We measured pollen mRNA decay during in planta development and in vitro maturation after transcriptional inhibition with ActinomycinD (ActD). Because five of these genes were also expressed in somatic cells we also measured RNA decay in BY2 cells after transcriptional inhibition with ActD. Ten of the mRNAs were highly stable during pollen development (t1/2 > 30 h), including all seven pollen-specific mRNAs. However, two mRNAs showed a logarithmic decrease as pollen development proceeded, both in planta and in vitro. In fact, for one of these two, GUT8-2b, the mRNA level decreased significantly within 3 h. Our results show that many pollen-expressed mRNAs are indeed long-lived but that at least some mRNAs undergo decay during pollen maturation. Thus, there is no overall cytoplasmic condition in pollen that stabilizes mRNAs and specific mRNA turnover mechanisms must exist. We detected reciprocal mRNA stabilities with two genes that are expressed in both BY2 cells and pollen. GUT15 mRNA, known to be unstable (t1/2 < 3 h) in BY2 cells, was highly stable in pollen. In contrast, GRP2 mRNA decayed in pollen but was highly stable in BY2 cells. Therefore, we conclude that mRNA stability can be tissue-specific.

Last Modified: 8/31/2014
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