In:
New Phytologist, Wiley, Vol. 218, No. 2 ( 2018-04), p. 579-593
Abstract:
Apple exhibits S ‐ RN ase‐based self‐incompatibility ( SI ), in which S ‐ RN ase plays a central role in rejecting self‐pollen. It has been proposed that the arrest of pollen growth in SI of Solanaceae plants is a consequence of the degradation of pollen rRNA by S ‐ RN ase; however, the underlying mechanism in Rosaceae is still unclear. Here, we used S 2 ‐ RN ase as a bait to screen an apple pollen cDNA library and characterized an apple soluble inorganic pyrophosphatase (Md PP a) that physically interacted with S ‐ RN ases. When treated with self S ‐ RN ases, apple pollen tubes showed a marked growth inhibition, as well as a decrease in endogenous soluble pyrophosphatase activity and elevated levels of inorganic pyrophosphate ( PP i). In addition, S ‐ RN ase was found to bind to two variable regions of Md PP a, resulting in a noncompetitive inhibition of its activity. Silencing of Md PP a expression led to a reduction in pollen tube growth. Interestingly, tRNA aminoacylation was inhibited in self S ‐ RN ase‐treated or Md PP a‐silenced pollen tubes, resulting in the accumulation of uncharged tRNA . Furthermore, we provide evidence showing that this disturbance of tRNA aminoacylation is independent of RN ase activity. We propose an alternative mechanism differing from RNA degradation to explain the cytotoxicity of the S ‐ RN ase apple SI process.
Type of Medium:
Online Resource
ISSN:
0028-646X
,
1469-8137
DOI:
10.1111/nph.2018.218.issue-2
Language:
English
Publisher:
Wiley
Publication Date:
2018
detail.hit.zdb_id:
208885-X
detail.hit.zdb_id:
1472194-6
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