Physiological quality and amylase enzyme expression in maize seeds

Abstract

The physiological quality of maize seeds is affected by the genotype. Thus, the study of expression of genes associated with this characteristic is important in the genotype selection process in breeding programs. The aim of this research was to study the expression of amylase enzymes associated with physiological quality of maize seeds with different genotypes and seed sizes. We further sought to assess the expression of these enzymes in dry and soaked seeds The experiment was conducted in the experimental area and the Central Seed Laboratory of the Department of Agriculture of the Universidade Federal de Lavras. Seeds of four maize inbred lines were used, classified in two sizes. The physiological quality of the seeds was evaluated by means of germination, seedling emergence, seedling emergence speed index and accelerated aging test. Expression of the alpha amylase enzyme was evaluated by the electrophoresis technique and expression of the alpha amylase B73, alpha amylase (LOC542522) and beta amylase 5 (amyb5) genes was studied by the qRT-PCR technique in dry and soaked seeds of the inbred lines. There is differentiated expression of amylase enzymes in maize seeds of inbred lines with different levels of physiological quality. higher expression of amylase enzymes is observed in soaked maize seeds. The expression of transcripts is higher in smaller as wellas in soaked maize seeds of inbred lines.Index terms: Zea Mays, seed quality, qRT-PCR. RESUMOA qualidade fisiológica de sementes de milho é influenciada pelo genótipo. Assim, o estudo da expressão de genes associados a essa característica é importante no processo de seleção de genótipos em programas de melhoramento. O objetivo neste trabalho foi estudar a expressão das enzimas amilases associadas à qualidade fisiológica de sementes de milho, de diferentes genótipos e tamanhos de sementes. Objetivou-se ainda avaliar a expressão dessas enzimas em sementes secas e embebidas. O experimento foi conduzido em área experimental e no Laboratório Central de Sementes do Departamento de Agricultura da Universidade Federal de Lavras. Foram utilizadas sementes de quatro linhagens de milho, classificadas em dois tamanhos. A qualidade fisiológica das sementes foi avaliada por meio dos testes de germinação, emergência de plântulas, índice de velocidade de emergência de plântulas e envelhecimento artificial.A expressão da enzima α-amilase foi avaliada pela técnica de eletroforese e a expressão dos genes alpha amylase B73, alpha amylase (LOC542522) e beta amylase 5 (amyb5), foi estudada pela técnica de qRT-PCR em sementes secas e embebidas das linhagens. Há expressão diferenciada das enzimas amilases em sementes de linhagens com diferentes níveis de qualidade fisiológica. Maior expressão das enzimas amilases é observada em sementes de milho de menor tamanho e embebidas.Termos para indexação: Zea Mays, qualidade de sementes, qRT-PCR.

Indirect Selection for Drought Tolerance in Maize Through Agronomic Traits and Seeds

“…However, Oliveira et al (2013) points out that in addition to the amylase genes, several other genes may be involved in controlling the physiological quality of seeds trait, as an example, the genes directly related to respiration.…”

“…Andrade et al (2013), with assessments at the fourth and seventh day after seeding, accounting was used the methodology proposed by Oliveira et al (2013). The extraction of heat resistant proteins was performed according to the methodology described by Andrade et al (2013).…”

Importance of amylases for physiological quality in maize seeds

“…Some research has shown that the physiological quality of maize seed (Zea mays) is inluenced not only by environmental factors, but also by the genotype and its interactions with the environment Importance of amylases in seed quality (HOECKER et al, 2006;REIS et al, 2011;OLIVEIRA et al, 2013;. Many authors such as Rood et al (1990), Causse et al (1995), Gomes et al (2000), José et al (2004b), Hoecker et al (2006 and Reis et al (2011) relate quality to the inluence of heterosis or hybrid vigor in seed germination.…”

“…Paleg (1965), in biochemical studies manipulating α-amylase synthesis and subsequent hydrolysis of the seed reserves, found a direct relationship between gibberellin synthesis and maize heterosis. According to Rood et al (1990) and Oliveira et al (2013), maize lineages are less vigorous than their descendant hybrids, in part because of gibberellin deiciency. These authors also found a positive correlation between seedling gibberellin content and growth rate, leaf area, and height of maize plants.…”

“…It is in this context that α-and β-amylase expression can be associated with the physiological quality of maize seed. However, Oliveira et al (2013) found differential expression of amylase enzymes in seeds from lineages with different levels of physiological quality, and noted that the highest expression of these enzymes does not necessarily occur in higher quality seed lineages. Andrade et al (2013) also found that in addition to the amylase enzymes, the LEA (late embryogenesis abundant) and SOD (superoxide dismutase) proteins are also related to physiological quality in maize seeds.…”