The carotenoid and abscisic acid content of viviparous kernels and seedlings ofZea mays L.

Abstract

Carotenoid and abscisic acid (ABA) levels were determined in endosperm, embryos and seedlings of wild-type and viviparous (vp) mutants ofZea mays L. Carotenoid concentrations were determined by absorption spectrometry following purification by high-performance liquid chromatography and ABA concentrations by combined gas chromatography-mass spectrometry. Lutein and zeaxanthin were the terminal carotenoids in wild-type tissue. The carotenoid profiles ofvp-1 andvp-8 tissue were similar to that of the wild type; invp-2, vp-5, vp-7 andvp-9 carotenogenesis was blocked at early stages so that xanthophylls were absent. Except forvp-1, where the ABA content was similar to the wild type, the ABA content ofvp embryos was substantially reduced, to 6-16% of the corresponding wild type. Thus, the absence of xanthophylls was associated with reduced ABA content, which was in turn correlated with vivipary. Kernels ofvp-8 had a reduced ABA content although xanthophylls were present. Seedlings of carotenoid-deficient mutants rescued from viviparous kernels contained less ABA than did wild-type seedlings grown in the same way. Furthermore, the ABA concentration of such seedlings did not increase in response to water deficit. Conversely,vp-1 seedlings contained normal levels of carotenoids and ABA. Carotenoid-deficient seedlings did not contain appreciable amounts of chlorophyll so that chloroplast development was not normal. Thus ABA-deficiency could be associated with abnormal plastid development rather than the absence of carotenoids per se.

Distinction between the Responses of Developing Maize Kernels to Fluridone and Desiccation in Relation to Germinability, α-Amylase Activity, and Abscisic Acid Content

“…1), as has been shown in other cultivars of maize (7,8). Germination ofviviparous (vp) mutants ofmaize has been attributed to either ABA-deficiency (3,16,23) or ABA-insensitivity (16). The chemically induced viviparous response occurs in both the embryo and the aleurone layer ( Figs.…”

Gibberellins and Seed Development in Maize. I. Evidence That Gibberellin/Abscisic Acid Balance Governs Germination versus Maturation Pathways

“…Mutants of Arabidopsis and tomato that are deficient in ABA synthesis have impaired seed maturation and dormancy (Koornneef and van der Veen, 1980;Koornneef et al, 1982). In maize (Zea mays L.), ABA-deficient mutants are viviparous, precociously germinating on the ear during kernel development (Robertson, 1955;Neill et al, 1986).…”

Quantitative trait loci for callus initiation and totipotency in maize (Zea mays L.)

“…The viviparous mutants in maize are associated with decreased or deWcient production of abscisic acid (ABA), a hormone involved in, among other roles, seed maturation and dormancy (Neill et al 1986;Tan et al 1997). The main and epistatic QTL observed herein in the mean across years for both non-transformed and transformed data in bins 1.08, 1.10, 2.04/5, 3.06, and 5.03/4 are in the same or bordering bins as genes that have mutant alleles with viviparous phenotypes (e.g., vp1-vp14 and w3), while the epistatic QTL in bin 2.04 is in the same bin as glossy11, which sometimes has a viviparous phenotype (MaizeGDB, http://www.maizegdb.org/).…”