| Abstract Detail
Seed Biology Shen-Miller, J. [1], Xie, Y. [2], Wooding, K. [3], Yang, Y. [3], Villa, S. [4], Zhang, H. [3], Lindner, P. [5], Loo, J. [3], Clarke, S. [4]. Exceptional longevity of fruits of Nelumbo nucifera: heat-hardy (100oC) proteins. Fruits (hard pericarp-containing seeds) of Nelumbo nucifera (sacred lotus) are the longest living (1300 y) known in plants. Nelumbo seed tissues contain abundant hardy proteins that remain soluble to high temperature (110oC). The total content and heat stability of seed proteins of a 549-y-old fruit are indistinguishable from those of modern controls. Nelumbo chaperonins are more abundant and more heat stable than those of French beans and wheat. At >80oC, the solubility of high molecular-weight proteins (>78 kDa) decreases in beans and wheat (half-life seed longevity ~8-16 y) but remains appreciable in old and modern Nelumbo. Heat-stable proteins (100oC) of Nelumbo embryo-axes, cotyledons and pericarp* by peptide sequencing (nano-LC, tandem-MS), Western blots** and bioassy^ show them to share sequence identity or homology with the following proteins of plants, fungi, metazoans, cyanobacteria and prokaryotes (kDa corresponding to those of protein standards on SDS-PAGE gels of Nelumbo, or Mr): ~200 kDa, phosphate ABC transporter/vitamin B6-binding glycine dehydrogenase-P/poly (ADP-ribose) polymerase; ~100 kDa, nucleolin; ~85 kDa, vitamin B12-indenpendent methionine synthase/Hsp 80/enolase; ~50 kDa, EF 1-alpha/Ser-Thr kinase/vicillin/enolase; ~37 kDa, actin/vicillin precursor/aldose reductase/Pi-ta protein; ~25 kDa, seed-maturation protein/dehydrin**/triosephosphate isomerase/chaperonin cpn20and**/Cys peroxiredoxin/glutathione transferase/L-isoaspartyl methyltransferase**,^; ~15 kDa, Cu-Zn superoxide dismutase/Hsp 18*/cyclophilin 2*/translation-controlled tumor protein homolog (TCTP)*/ADP ribosylation factor*. Many of the proteins noted above are necessity- and stress-related species whose possible functions (cf. defense, repair, reserve, rescue, signal transduction, etc.) in the long-term maintenance of seed viability will be discussed.
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1 - University California, Los Angeles, Inst Geophys Planetary Phys-Ctr Stdy Evol Orig Life; Dept Ecol, Evol Biol, 5687 Geol. Bldg., Hilgard Ave., Los Angeles, CA, 90095-1567, USA
2 - UCLA, Chem/Biochm
3 - UCLA, Chem/Biochem
4 - UCLA, Mol Biol Inst
5 - Univ Regensburg, Inst Microbiol
Keywords:
longest-living fruits
abiotic and biotic stresses,
defence- and repair-related proteins,
heat-stable (100C) proteins, Nelumbo nucifera.
Presentation Type: ASPB Minisymposium
Session: M07
Location: Continental C/Hilton
Date: Sunday, July 8th, 2007
Time: 4:35 PM
Number: M07002
Abstract ID:637 |
