RESUMO
BACKGROUND: Aluminium (Al) toxicity is the main factor limiting the crop production in acid soils and barley (Hordeum vulgare L.) is one of the most Al-sensitive of the small-grained cereals. The major gene for Al tolerance in barley is HvAACT1 (HvMATE) on chromosome 4H which encodes a multidrug and toxic compound extrusion (MATE) protein. The HvAACT1 protein facilitates the Al-activated release of citrate from root apices which protects the growing cells and enables root elongation to continue. A 1 kb transposable element-like insert in the 5' untranslated region (UTR) of HvAACT1 is associated with increased gene expression and tolerance and a PCR-based marker is available to score for this insertion. RESULTS: We screened a wide range of barley genotypes for Al tolerance and identified a moderately tolerant Chinese genotype named CXHKSL which did not show the typical allele in the 5' UTR of HvAACT1 associated with tolerance. We investigated the mechanism of Al tolerance in CXHKSL and concluded it also relies on the Al-activated release of citrate from roots. Quantitative trait loci (QTL) analysis of double haploid lines generated with CXHKSL and the Al-sensitive variety Gairdner mapped the tolerance locus to the same region as HvAACT1 on chromosome 4H. CONCLUSIONS: Our results show that the Chinese barley genotype CXHKSL possesses a novel allele of the major Al tolerance gene HvAACT1.
Assuntos
Alelos , Alumínio/toxicidade , Hordeum/genética , Proteínas de Plantas/genética , Regiões 5' não Traduzidas , Ácido Cítrico/metabolismo , Elementos de DNA Transponíveis , DNA de Plantas/genética , Regulação da Expressão Gênica de Plantas , Genótipo , Hordeum/efeitos dos fármacos , Malatos/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Locos de Características Quantitativas , Análise de Sequência de DNARESUMO
An IR imaging system based on a microelectromechanical system (MEMS) microcantilever is uncooled, low-cost, and more reliable than traditional systems. However, it is difficult to avoid unwanted shape distortions in fabrication, which can degrade image quality in many ways, so we use holography to compensate for these shape distortions in an optical readout focal plane array (FPA) IR imaging system. The experiment shows that it is a feasible way to improve system performance, especially when it is too difficult to perfect the techniques of an FPA fabrication.