Expression of ACO1, ERS1 and ERF1 genes in harvested bananas in relation to heat-induced defense against Colletotrichum musae

Rao

et al. 2016

Sci Rep

Self Cite

Internal browning (IB), a physiological disorder (PD) that causes severe losses in harvested pineapple, can be induced by exogenous gibberellins (GAs). Over the years, studies have focused on roles of Gibberellin 2-oxidase (GA2oxs), the major GAs catabolic enzyme in plants, in the regulation of changes in morphology or biomass. However, whether GA2oxs could regulate PD has not been reported. Here, a full-length AcGA2ox cDNA was isolated from pineapple, with the putative protein sharing 23.59% to 72.92% identity with GA2oxs from five other plants. Pineapples stored at 5 °C stayed intact, while those stored at 20 °C showed severe IB. Storage at 5 °C enhanced AcGA2ox expression and decreased levels of a GAs (GA4) ‘compared with storage at 20 °C. However, at 20 °C, exogenous application of abscisic acid (ABA) significantly suppressed IB. ABA simultaneously upregulated AcGA2ox and reduced GA4. Ectopic expression of AcGA2ox in Arabidopsis resulted in reduced GA4, lower seed germination, and shorter hypocotyls and roots, all of which were restored by exogenous GA4/7. Moreover, in pineapple, GA4/7 upregulated polyphenol oxidase, while storage at 5 °C and ABA downregulated it. These results strongly suggest the involvement of AcGA2ox in regulation of GAs levels and a role of AcGA2ox in regulating IB.

Section: Methodsmentioning

confidence: 99%

Mechanism of internal browning of pineapple: The role of gibberellins catabolism gene (AcGA2ox) and GAs

Rao

et al. 2016

Sci Rep

Self Cite

“…Considerable research has been carried out in the past to elucidate the molecular events of ACC oxidase gene involved in banana fruit ripening [41]. However, little information is available regarding the respective function of each member of ACC oxidase multigene family.…”

Section: Discussionmentioning

confidence: 99%

“…It is worthwhile to note that no remarkable change was observed between high-throughput transcriptomic data and the results obtained by real-time RT-PCR analysis. Several studies have demonstrated a close relationship between the expression levels of ethylene biosynthesis genes and those of ethylene signaling genes [41]. …”

Section: Discussionmentioning

confidence: 99%

Global Transcriptomic Analysis of Targeted Silencing of Two Paralogous ACC Oxidase Genes in Banana

Xia

Kuan

Chiu

et al. 2016

IJMS

Among 18 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase homologous genes existing in the banana genome there are two genes, Mh-ACO1 and Mh-ACO2, that participate in banana fruit ripening. To better understand the physiological functions of Mh-ACO1 and Mh-ACO2, two hairpin-type siRNA expression vectors targeting both the Mh-ACO1 and Mh-ACO2 were constructed and incorporated into the banana genome by Agrobacterium-mediated transformation. The generation of Mh-ACO1 and Mh-ACO2 RNAi transgenic banana plants was confirmed by Southern blot analysis. To gain insights into the functional diversity and complexity between Mh-ACO1 and Mh-ACO2, transcriptome sequencing of banana fruits using the Illumina next-generation sequencer was performed. A total of 32,093,976 reads, assembled into 88,031 unigenes for 123,617 transcripts were obtained. Significantly enriched Gene Oncology (GO) terms and the number of differentially expressed genes (DEGs) with GO annotation were ‘catalytic activity’ (1327, 56.4%), ‘heme binding’ (65, 2.76%), ‘tetrapyrrole binding’ (66, 2.81%), and ‘oxidoreductase activity’ (287, 12.21%). Real-time RT-PCR was further performed with mRNAs from both peel and pulp of banana fruits in Mh-ACO1 and Mh-ACO2 RNAi transgenic plants. The results showed that expression levels of genes related to ethylene signaling in ripening banana fruits were strongly influenced by the expression of genes associated with ethylene biosynthesis.

“…Isso mostra como a resposta do fruto ao tratamento térmico é variável, pois não há pesquisas indicando como o calor, um sinal físico, é percebido pelos tecidos do fruto e transformado em sinais químicos que finalmente levam às mudanças no amadurecimento e nas respostas de defesa. De acordo com Zhu et al (2011) o tratamento térmico como um sinal físico pode ser sentido pelas bananas através da inibição da expressão do gene receptor de etileno do mesmo modo que o etileno é percebido, mas não se sabe se esta percepção ocorre de forma semelhante para o mamão. Segundo Yang et al (2013), o mecanismo de ação do etileno consiste na sua ligação a uma molécula receptora localizada na membrana do reticulo endoplasmático que, por meio de fosforilação, desencadeia uma cascata de transdução de sinais até a ativação de genes codificadores de enzimas, que mediam as alterações físicas e bioquímicas que acompanham o processo de amadurecimento dos frutos.…”

Section: De Acordo Comunclassified

“…Quando os mamões foram transferidos da refrigeração para o armazenamento ambiente, observamos novamente a formação de um pico de atividade da ACC oxidase. No entanto, este pico ocorreu no 21º dia para os frutos não tratados e no 22º dia para os tratados (Figura 4B) Zhu et al (2011). demonstraram que a expressão do gene da enzima ACC oxidase oscilou entre picos de maior e menor expressão em bananas tratadas e não tratadas termicamente.Segundo SONG et al (2005), a expressão dos genes da ACC oxidase pode ser regulada por fatores ambientais, de desenvolvimento ou específicos do tecido dos frutos.…”

unclassified

Efeito do tratamento hidrotérmico quarentenário na pós-colheita de mamão

Resende¹

Hydrothermal quarantine treatment effect in papaya postharvest Papaya is a climacteric fruit whose transformations resulting from ripening occur rapidly after harvest and are triggered by the production of ethylene and increased respiration, being a very perishable fruit. The use of technologies such as heat treatment and cooling is necessary because they eliminate eggs and/or larvae of fruit fly and control the microorganisms' growth, increasing the shelf life of this fruit. However, they can cause changes in the processes of maturation and damage in the plasma membrane integrity. Thus, the project aims to study the physiology, biochemistry, quality and papaya postharvest preservation after application of hydrothermal quarantine treatment and refrigerated storage. Golden papaya in maturity stage 1 were divided into two batches, one being subjected to hydrothermal quarantine treatment to 47 °C ± 1 °C for 20 minutes, followed by immersion in cold water to 11 °C ± 1 °C for the same period and the other lot used as a control (no hydrothermal treatment). Part of the fruits were stored at 22 ± 1 °C and 85 ± 5% RH for 7 days and some at 11 ± 1 °C and 85 ± 5% RH for 20 days, followed by storage at 22 ± 1 °C and 85 ± 5 % RH for 3 days. The papayas were evaluated with respect to biochemical and physiological aspects and organoleptic characteristics. We observed that the respiratory rate, ethylene production, the ascorbic acid content and the accumulated loss of fresh weight decreased in heat-treated fruit, especially when they are stored under refrigeration. Sensory analysis showed that the heat treated fruit were preferred in taste and texture and decrease the amount of linalool present in papayas subjected to cold storage showed that the cold negatively affected the scent. The enzymes analyzed did not possess a pattern of activity during the evaluation days. Thus, future studies on the expression of genes related to the ripening papayas are needed for a better understanding of the solutions when applying the hydrothermal quarantine treatments and refrigerated storage.