Temperature sensitivity as a general phenomenon in a collection of chlorophyll-deficient mutants of sweetclover (Melilotus alba)

Chi Ming Yang, John C. Osterman, John Markwell

Research output: Contribution to journalArticle

6 Scopus citations


A collection of chlorophyll (Chl)-deficient mutants of sweetclover (Melilotus alba) with defects in eight nuclear loci were grown at 17 or 26° C. Plants grown at either temperature were examined for Chl content, Chl a/b ratio, expression of the light-harvesting complex II (LHC-II) apoproteins, and protochlorophyllide (Pchlide) biosynthetic capacity. Except for the ch4 mutant, the parental strain and all mutants accumulate more Chl when grown at 26° C than at 17° C. The ch5 mutants, lacking Chl b under any growth condition, and the ch12 mutant showed little temperature-dependent phenotypic plasticity, whereas this was a marked phenomenon in the other mutants. The ch10 and ch11 mutants demonstrated extreme temperature sensitivity with regard to the production of Chl b and the Chl b-binding LHC-II apoproteins. When excised trifoliolates were supplemented with exogenously supplied δ-aminolevulinic acid, only the ch4 mutant was markedly impaired in the ability to produce Pchlide. These data indicate that temperature-sensitive phenotypic plasticity is a common phenomenon of chlorophyll-deficient mutants and substantiate that only a minority of Chl-deficient mutants is impaired in the biosynthesis of Chl.

Original languageEnglish (US)
Pages (from-to)31-40
Number of pages10
JournalBiochemical Genetics
Issue number1-2
Publication statusPublished - Feb 1 1990



  • Melilotus alba
  • chlorophyll deficiency
  • light-harvesting complex
  • sweet-clover
  • temperature sensitive

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Biochemistry
  • Molecular Biology
  • Genetics

Cite this