ABSTRACT
Objective: To clone novel member of alkaline/neutral invertase (NI) gene in a rare and endangered medicinal plant of Dendrobium officinale, conduct bioinformatic analysis and detect the quantitative expression in different organs. Methods: Primers were designed according to NI gene segment which was selected from leaf transcriptome sequencing results of D. officinale. The full-length cDNA of NI gene was cloned via homology-based cloning and rapid amplification of cDNA ends (RACE) approach. The physical and chemical properties, secondary structure and tertiary structure of NI protein were forecasted and analyzed using related software. The expression levels of NI gene in roots, stems, and leaves of D. officinale were detected using real-time PCR. Results: A novel gene encoding a NI protein was cloned from D. officinale. This gene (named as DoNI2, GenBank accession number: KY794404) had a total length of 2 397 bp with an open reading frame of 1 836 bp, and encoded a predicted polypeptide of 611 amino acids with a molecular weight of 69 050. Bioinformatics predicted that the isoelectric point of DoNI2 gene encoding protein was 6.38, the instability coefficient was 44.95, and the hydrophobic coefficient was −0.232. RT-PCR showed that DoNI2 gene expressed in all organs with highest expression level in stems and the lowest in roots. DoNI2 gene expression was significantly positively correlation with NI enzymatic activities at different growth years of D. officinale. Conclusion: The full length cDNA sequence in a mitochondrial DoNI2 gene was identified, facilitating future functional analysis of the gene involving in the regulation of sugar metabolism in D. officinale.
ABSTRACT
Invertases play an essential role in partitioning photosynthates between storage and growth. The objective of this study was to evaluate the activity of acid and neutral invertases and the role they play in controlling the accumulation of sucrose in sugarcane as a result of the application of plant regulators in the beginning of the cropping season.A randomized block experimental design was adopted, with five replicates.The treatments consisted in the application of three plant regulators of the class of growth inhibitors (Sulfomethuron-methyl - 20g ha-1, Glyphosate - 0.4L ha-1, and Compounds from organic carboxylic radicals + Glyphosate - 1L ha-1 + 0.15L ha-1), in addition to a control (natural ripening).The acid and neutral invertase levels are affected in different ways and intensities, due to the active principle used as ripening agent and to the weather conditions.In sugarcane variety RB85-5453, with the conditions described in this experiment, it is suggested high levels of soluble acid invertase in relation to levels of neutral invertase; however, the first was characterized by high sucrose content in the stalks.Inverse correlation could be established for sugarcane variety RB85-5453 between soluble acid invertase levels and effective sucrose accumulation in the stalks.
Invertases desempenham um papel essencial no particionamento de fotossintatos entre armazenamento e crescimento. O objetivo deste estudo foi avaliar a atividade das enzimas invertases ácida e alcalina (neutra) e o papel que desempenham no controle do acúmulo de sacarose em cana-de-açúcar, como resultado da aplicação de reguladores vegetais no início da época de colheita. O delineamento experimental utilizado foi em blocos ao acaso, com cinco repetições. Os tratamentos consistiram na aplicação de três reguladores vegetais da classe dos inibidores de crescimento (Sulfometuron-metil - 20g ha-1, Glifosato - 0,4L ha-1, e Compostos de radicais carboxílicos orgânicos + Glifosato - 1L ha-1 + 0,15L ha-1), além do controle (maturação natural). Os níveis das invertases ácida e neutra são afetados de maneiras e intensidades distintas, devido ao princípio ativo utilizado como agente de maturação e das condições meteorológicas. Para a variedade RB85-5453, nas condições descritas neste experimento, sugerem-se níveis elevados de SAI em relação à NI;no entanto, a primeira foi caracterizada por um elevado teor de sacarose nos colmos. Correlação inversa pode ser estabelecida entre a atividade da invertase ácida e o acúmulo de sacarose.