Impact of low-temperature stress on general phenylpropanoid and anthocyanin pathways: Enhancement of transcript abundance and anthocyanin pigmentation in maize seedlings
- 1.7k Downloads
Changes in anthocyanin content and transcript abundance for genes whose products function in general phenylpropanoid metabolism and the anthocyanin pathway were monitored in maize (Zea mays L.) seedlings during short-term, low-temperature treatment. Anthocyanin and mRNA abundance in sheaths of maize seedlings increased with the severity and duration of cold. Anthocyanin accumulation was found in all tested lines that were genotypically capable of any anthocyanin production. Within 24 h of transferring 7-d maize (B37N) seedlings to 10° C, phenylalanine ammonia-lyase (Pal) (EC 220.127.116.11)-homologous and chalcone synthase (C2) (EC 18.104.22.168) transcript levels increased at least 8- and 50-fold, respectively, and 4-coumarate:CoA ligase (4Cl) (EC 22.214.171.124)-homologous and chalcone isomerase (Chi) (EC 126.96.36.199)-homologous transcripts increased at least 3-fold over levels in unstressed plants. Time-course studies showed thatPal (EC 188.8.131.52) andC2-transcript levels remained relatively constant for the first 12 h of cold stress, dramatically increased over the next 12 h, and declined to pretreatment levels within 2 d of returning coldstressed seedlings to ambient (25° C) temperature. Transcripts4Cl (EC 184.108.40.206) andChi (EC 220.127.116.11) increased in abundance within 6 h of cold stress, exhibited no further increase over the next 36 h, and declined to pretreatment levels upon returning seedlings to 25° C. Transcripts homologous to two regulatory (R, C1) and three structural (A1,A2, andBz2) anthocyanin genes increased at least 7- to 10-fold during cold treatment, exhibiting similar kinetics of accumulation as forPal (EC 18.104.22.168) andC2 transcripts. Transcripts encoded byBz1, the anthocyanin structural gene for UDP:glucose-flavonol glucosyltransferase (EC 22.214.171.124), were relatively abundant in control tissues and exhibited only a transient increase during the cold period. Our studies suggest that the genes of the anthocyanin biosynthetic pathway can be consideredcor (Cold-Regulation) genes, and because this pathway is well defined, it is an excellent subject for characterizing plant molecular responses to low temperatures.
Key wordsAnthocyanin Cold stress mRNA Zea mays
Unable to display preview. Download preview PDF.
- Coe, E.H. Jr., Neuffer, M.G., Hoisington, D.A. (1988) The genetics of corn. In: Corn and corn improvement, pp. 181–258, Sprague, G.F., Dudley, J.W., eds. Am. Soc. Agronomy, MadisonGoogle Scholar
- Cone, K.C., Burr, B. (1989) Molecular and genetic analysis of the light requirement for anthocyanin synthesis in maize. In: Genetics of flavonoids, pp. 143–145, Styles, D.E., Gavazzi, G.A., Racchi, M.L., eds. Unicopli, MilanGoogle Scholar
- Dellaporta, S.L., Greenblatt, I., Kermicle, J.L., Hicks, J.B., Wessler, S.R. (1987) Molecular cloning of the maizeR-nj allele by transposon tagging withAc. In: Chromosome structure and function: Impact of new concepts, 18th Stadler Genetics Symposium, pp. 263–282, Gustafson, J.P., Appels, R., eds. Plenum Press, New YorkGoogle Scholar
- Levitt, J. (1980) Responses of plants to environmental stresses, vol I: Chilling, freezing, and high temperature stresses. Academic Press, New YorkGoogle Scholar
- Ludwig, S.R., Habera, L.F., Dellaporta, S.L., Wessler, S.R. (1989) Lc, a member of the maizeR gene family responsible for tissue-specific anthocyanin production, encodes a protein similar to transcriptional activators and contains themyc-homology region. Proc. Natl. Acad. Sci. USA86, 7092–7096CrossRefPubMedPubMedCentralGoogle Scholar
- Mennssen, A., Höhmann, S., Martin, W., Schnable, P.S., Peterson, P.A., Saedler, H., Gierl, A. (1990) TheEn/Spm transposable element of Zea mays contains splice sites at the termini generating a novel intron from adSpm element in theA2 gene. EMBO J. 9, 3051–3057Google Scholar
- van Tunen, A.J., Koes, R.E., Spelt, C.E., van der Krol, A.R., Stuitje, A.R., Mol, J.N.M. (1988) Cloning of the two chalcone flavanone isomerase genes fromPetunia hybrida: Coordinate, light-regulated and differential expression of flavonoid genes. EMBO J. 7, 1257–1263PubMedPubMedCentralGoogle Scholar