Nondestructive analysis of senescence in mesophyll cells by spectral resolution of protein synthesis-dependent pigment metabolism

Alan Philip Gay, Howard Thomas, Maria Roca, Caron Louise James, Janet Taylor, Jeremy John Rowland, Helen Joan Ougham

Research output: Contribution to journalArticlepeer-review

14 Citations (SciVal)

Abstract

Over 6 d of dark-induced senescence, leaf segments of wild-type Lolium temulentum lost > 96% chlorophyll a + b; leaves from plants containing a staygreen mutation introgressed from Festuca pratensis, which has a lesion in the senescence-associated fragmentation of pigment-proteolipid complexes, retained over 43% of total chlorophyll over the same period. Mutant segments preferentially retained thylakoid membrane proteins (exemplified by LHCP II) but lost other cellular proteins at the same rate as wild-type tissue. The protein synthesis inhibitor D-MDMP inhibited chlorophyll degradation and partially prevented protein loss in both genotypes, but tissues treated with the ineffective L-stereoisomer were indistinguishable from water controls. Principal-components analysis of leaf reflectance spectra distinguished between genotypes, time points and D-MDMP treatments, showing the disruption of pigment metabolism during senescence brought about by the staygreen mutation, by inhibition of protein synthesis and by combinations of the two factors. The build-up of oxidized, dephytylated and phaeo-derivatives of chl a during senescence of staygreen tissue was prevented by D-MDMP and associated with characteristic difference spectra when senescent mutant tissue was compared with wild-type or inhibitor-treated samples. The suitability of senescence as a subject for systems biology approaches is discussed.
Original languageEnglish
Pages (from-to)663-674
Number of pages12
JournalNew Phytologist
Volume179
Issue number3
DOIs
Publication statusPublished - 2008

Keywords

  • chlorophyll
  • chloroplast
  • MDMP
  • multivariate analysis
  • mutant
  • senescence
  • Systems Biology

Fingerprint

Dive into the research topics of 'Nondestructive analysis of senescence in mesophyll cells by spectral resolution of protein synthesis-dependent pigment metabolism'. Together they form a unique fingerprint.

Cite this