Genetic Variation for Lettuce Seed Thermoinhibition Is Associated with Temperature-Sensitive Expression of Abscisic Acid, Gibberellin, and Ethylene Biosynthesis, Metabolism, and Response Genes
| Autor: | Kent J. Bradford, Jason Argyris, David W. Still, Eiji Hayashi, Peetambar Dahal |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Hot Temperature
Genotype Light Pyridones Physiology Quantitative Trait Loci Germination Lactuca Plant Science Biology Quantitative trait locus chemistry.chemical_compound Plant Growth Regulators Gene Expression Regulation Plant Botany Genetics Cluster Analysis Abscisic acid Plant Proteins Analysis of Variance Gene Expression Profiling Chromosome Mapping Genetic Variation food and beverages Plant physiology Lactuca serriola Ethylenes Lettuce biology.organism_classification Gibberellins chemistry Biochemistry RNA Plant Seeds Fluridone Gibberellin Abscisic Acid Signal Transduction Research Article |
| Zdroj: | Plant Physiology. 148:926-947 |
| ISSN: | 1532-2548 |
| DOI: | 10.1104/pp.108.125807 |
| Popis: | Lettuce (Lactuca sativa ‘Salinas’) seeds fail to germinate when imbibed at temperatures above 25°C to 30°C (termed thermoinhibition). However, seeds of an accession of Lactuca serriola (UC96US23) do not exhibit thermoinhibition up to 37°C in the light. Comparative genetics, physiology, and gene expression were analyzed in these genotypes to determine the mechanisms governing the regulation of seed germination by temperature. Germination of the two genotypes was differentially sensitive to abscisic acid (ABA) and gibberellin (GA) at elevated temperatures. Quantitative trait loci associated with these phenotypes colocated with a major quantitative trait locus (Htg6.1) from UC96US23 conferring germination thermotolerance. ABA contents were elevated in Salinas seeds that exhibited thermoinhibition, consistent with the ability of fluridone (an ABA biosynthesis inhibitor) to improve germination at high temperatures. Expression of many genes involved in ABA, GA, and ethylene biosynthesis, metabolism, and response was differentially affected by high temperature and light in the two genotypes. In general, ABA-related genes were more highly expressed when germination was inhibited, and GA- and ethylene-related genes were more highly expressed when germination was permitted. In particular, LsNCED4, a gene encoding an enzyme in the ABA biosynthetic pathway, was up-regulated by high temperature only in Salinas seeds and also colocated with Htg6.1. The temperature sensitivity of expression of LsNCED4 may determine the upper temperature limit for lettuce seed germination and may indirectly influence other regulatory pathways via interconnected effects of increased ABA biosynthesis. |
| Databáze: | OpenAIRE |
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