Analysis of MaACS2, a stress-inducible ACC Synthase Gene in Musa acuminata AAA Group Cultivar Pisang Ambon

Ethylene  has  an important function in plant growth and development. Ethylene  production  generally  increases  in  response  to  pathogen  attacks  and other  environmental  stress  conditions.  The  synthesis  of  this phytohormone  is regulated  by  two  enzymes,  ACC  synthase  (ACS)  and  ACC  oxidase  (ACO).  ACC synthase is encoded by a multigene  that  regulates  the  production  of ACC, after  which  this  precursor  is  converted  into  ethylene  by  ACO.  Pisang  Ambon (Musa  sp. AAA group), a banana cultivar originating from Indonesia, has nine ACS genes (MaACS  1-9) and one ACO gene (MaACO).  One  of  the  banana  ACS genes,  MaACS2,  is  stress-inducible.  In  this  research,  we  have  investigated  the expression  profile  of  MaACS2  in  the  roots  and  leaf  tissues  of  infected  tissue culture  plants.  Quantification  of  gene  expression  was analyzed using Real-Time PCR (qPCR) using  Ma18srRNA  and  MaGAPDH  as reference genes.  The results showed  nine-to  ten  fold  higher  MaACS2  expression  levels in  the  infected  roots tissues  compared to  the  uninfected roots  tissues. However,  MaACS2 expression in the leaves was only detected in infected tissue

Banana Flower-Insect Interaction: Alpha-Pinene as Potential Attractant for the Insect Vector of Banana Blood Disease

Volatile metabolites are produced by plants for self-defense and as communication mediators with the environment. Terpenes are volatiles emitted as odorant cues for herbivores and microorganisms. This study was aimed to investigate volatile metabolites produced by banana flowers that attract insect vectors of BBD. The volatile metabolites from banana flowers were extracted by headspace-solid phase microextraction (HS-SPME) and identified by gas chromatography–mass spectrometry (GC-MS). It was apparent that the concentrations of the metabolite alpha-pinene gradually increased from the first to the the third stage. Comparison of metabolites produced by symptomatic banana male flowers for BBD infection with non-symptomatic ones showed that the concentration of alpha-pinene was higher in symptomatic male flowers. In addition, preference for alpha-pinene was tested on three insect vector species (Rhodesiella bhutanensis, Drosophila sp., and Musca sp.), analyzed by M. Anova p<0.001, F(1.5) =12.539 and Duncan test. Results showed that the insect vectors were mostly attracted to 20 µl volume of alpha-pinene compared to the other volumes and that alpha-pinene functioned as an attractant to these insects. This research is important for the formulation of attractants for insect vectors of BBD to control transmission of banana blood disease

Agrobacterium tumefaciens-mediated Transformation of Embryogenic Callus and Somatic Embryos of the Banana cv “Ambon Lumut” (Musa acuminata)

Banana is one of the major fruit crops, though its conventional breeding has limitations, such as sterility and high polyploidy  levels.  Biotechnological  approach  using genetic  transformation  crop for improvement  offers  an alternative  solution.  In  this  study  a  protocol  was developed  for  establishing genetic  transformation  from embryogenic callus and somatic embryos of the banana cv Ambon Lumut . Embryogenic callus was obtained in ID4 medium (MS-based medium) supplemented with 1 mg L-1 IAA, 4 mg L-1 2,4D, and 0.03 g L-1 active charcoal. Embryogenic callus was transferred into liquid mediu m to establish somatic embryos. Embryogenic callus and somatic embryos were used for Agrobacterium tumefaciens-mediated transformation. A. tumefaciens strain A GL1, containing pART-TEST7 p lasmid with gfp gene as a reporter and CaM V35S as a promoter, was used for transformations. The embryogenic callus and somatic embryos were transformed using heat-shock method followed by centrifugation  (2000 rpm) and co-cult ivation in liquid medium containing acetosyringone (100 M) for 3 days. Results of the GFP analysis showed transient expression from gfp gene reporter in transformed embryogenic callus and somatic embryos. Transformation efficiency in somatic embryos (85,9%) was higher than  that in embryogenic callus (32.09%). PCR analysis using CaMV primer showed bands that compatible with CaMV35S promoter at 507 bp. This is a report showing establisment of embryogenic callus and somatic embryo culture transformation by using A. tumefaciens-mediated transformation protocol of the local banana cv Ambon Lumut. This study proved  the huge potential for genetic transformation of banana cv Ambon Lumut for crop improvement, such as pest or disease  resistance and abiotic factor stress tolerance. Keywords: banana; embryogenic callus; somatic embryos

Banana Flower-Insect Interaction: Alpha-Pinene as Potential Attractant for the insect Vector of Banana Blood Disease

Volatile metabolites are produced by plants for self-defense and as communication mediators with the environment. Terpenes are volatiles emitted as odorant cues for herbivores and microorganisms. This study was aimed to investigate volatile metabolites produced by banana flowers that attract insect vectors of BBD. The volatile metabolites from banana flowers were extracted by headspace-solid phase microextraction (HS-SPME) and identified by gas chromatography–mass spectrometry (GC-MS). It was apparent that the concentrations of the metabolite alpha-pinene gradually increased from the first to the the third stage. Comparison of metabolites produced by symptomatic banana male flowers for BBD infection with non-symptomatic ones showed that the concentration of alpha-pinene was higher in symptomatic male flowers. In addition, preference for alpha-pinene was tested on three insect vector species (Rhodesiella bhutanensis, Drosophila sp., and Musca sp.), analyzed by M. Anova p<0.001, F(1.5)=12.539 and Duncan test. Results showed that the insect vectors were mostly attracted to 20 μl volume of alpha-pinene compared to the other volumes and that alpha-pinene functioned as an attractant to these insects. This research is important for the formulation of attractants for insect vectors of BBD to control transmission of banana blood disease

Possibility of sap-feeding beetle, nitidulidae, as a spreading agent for blood disease bacterium on the banana plant

Banana blood disease (BBD) caused by blood disease bacterium (BDB) is one of the major diseases of Indonesian banana plants. The foraging activity of flower-visiting insects was suspected as the vectors of the disease. This study aims at analyzing the potential of the sap-feeding beetle, Nitidulidae, as a vector of BDB. Beetle collection was done by using purposive sampling method on three cultivars of banana inflorescence: Nangka, Klutuk, and Siem. The bacterium was isolated from the outside and the inside of beetle tissues and was followed with bacterial DNA extraction. Confirmation of bacterial cell culture as BDB was conducted by biochemical assay and PCR using 16S rDNA oligonucleotide. The findings revealed that the beetle population in the three cultivars of banana cultivars was Nangka (66%), Siem (19%) and Klutuk (16%). According to the biochemical assay and PCR result, it has been found that the bacterial cell culture was found positive as BDB, which was putative 79% and homolog with BDB that is in accordance with the data provided by NCBI. Thereby, the discovery of BDB in sap-feeding beetle, Nitidulidae, showed that the foraging activity has the potential as an agent of spreader of BDB in banana plants

Analysis of ethylene biosynthesis gene expression profile during titanium dioxide (TiO2) treatment to develop a new banana postharvest technology

Banana is an important crop that demands proper methods in postharvest handling. As a climacteric fruit, thebanana fruit ripening process is affected by ethylene. Several methods have been developed to extend the shelf life of a banana, such as using ethylene scrubbers. In this study, ttanium dioxide (TiO2), a photocatalyst, was used as an alternatve method to delay the fruit ripening process. The effect of TiO2 on the ripening‐related gene MaACS1 was investgated. Banana fruits were placed in a TiO2‐coated glass chamber and observed for ten days. Fruit ripening in the treated chamber was delayed for eight days compared to the control. Total RNA was extracted from control and TiO2‐treated fruit pulp and synthesized into cDNA. Reverse transcripton PCR was performed to investgate the gene expression, which showed that MaACS1 expression was relatvely lower than treated control. The fnding of these studies suggested that the TiO2 chamber has the potental to extend the shelf life of banana by delaying its ripening process and decreasing the expression of MaACS1. To the best of our knowledge, no previous study has investgated the effect of TiO2 on the expression of genes related to banana fruit ripening

Expression Study of Banana Pathogenic Resistance Genes

Banana is one of the world's most important trade commodities. However, infection of banana pathogenic fungi (Fusarium oxysporum race 4) is one of the major causes of decreasing production in Indonesia. Genetic engineering has become an alternative way to control this problem by isolating genes that involved in plant defense mechanism against pathogens. Two of the important genes are API5 and ChiI1, each gene encodes apoptosisinhibitory protein and chitinase enzymes. The purpose of this study was to study the expression of API5 and ChiI1 genes as candidate pathogenic resistance genes. The amplified fragments were then cloned, sequenced, and confirmed with in silico studies. Based on sequence analysis, it is showed that partial API5 gene has putative transactivationdomain and ChiI1 has 9 chitinase family GH19 protein motifs. Data obtained from this study will contribute in banana genetic improvement

Expression Analysis of 1-aminocyclopropane-1-carboxylic Acid Oxidase Genes in Chitosan-Coated Banana

Banana is a climacteric fruit in which ethylene plays an important role in the regulation of the ripening process. Though it is the most produced fruit in Indonesia, the current post-harvest technologies for exporting this fruit are not economically friendly. Chitosan is one of economical biopolymer for edible coating which can extend fruit shelf-life. However, little study focused on the effect of chitosan coating has been done on gene expression level. In this study, the expression levels of several 1-aminocyclopropan-1-carboxylic acid oxidase (ACO) genes, which is an enzyme to convert 1-aminocyclopropan-1-carboxylic acid to ethylene in banana were analyzed on day 0, 1, 3, 5, 7, and 9 after ethylene treatment. As a result, one gene (ID: Ma01_t11540.1) had a similar expression pattern in both control and chitosan-coated bananas while the other genes (ID: Ma03_t02700.1, Ma05_t09360.1, Ma06_t02600.1, Ma10_t01130.1) showed different expression patterns. Among these genes, two genes (ID: Ma05_t09360.1, Ma10_t01130.1) were expressed higher than the other genes and the peak was observed on day 3. It was indicated that chitosan coating might activate the ethylene biosynthesis pathway in banana while it delayed fruit ripening

Biodiversity of Bali Banana (Musaceae) and its Usefulness

Banana (Musa spp.) is one the most important agriculture commodities in Indonesia. Archeological and molecular evidences suggest that speciation of this herb occurred in Indonesia, leading to the high diversity in the archipelago. In Bali Island, banana is not only sought for food but as well as for their symbolic role in religious and cultural ceremonies. However, the high demand for bananas in Bali is not yet supported by the adequate production of local farms. This presented study aimed to investigate the diversity of banana cultivars or sub-species in Bali and its usefulness to determine preferable cultivars to cultivate. We recorded and characterized 43 banana cultivars in 10 villages that represent the 8 regencies and 1 city of Bali province. Out of the 43 cultivars, 7 were highly used and at least one cultivar was discovered in each of the studied village.  The presence of these cultivars in the study areas were confirmed by site visit and characterization of the fruits. Among the highly ranked cultivars or species, only biu kayu is unique to Bali as it was not found in the closest provinces of East Java and Madura. Hence, the results suggested that to improve the cultivation and production of these 7 highly used cultivars could be an appropriate solution to meet Bali demand of bananas. Furthermore, cultivating biu kayu would also help conservation effort since this cultivar is also currently listed as a rare genetic resource

Identification of Banana Plants from Unmanned Aerial Vehicles (UAV) Photos Using Object Based Image Analysis (OBIA) Method (A Case Study in Sayang Village, Jatinangor District, West Java)

  Banana is one of the leading fruit commodities of Indonesia and ranks the sixth position as one of the largest banana producers in the world. There are more than 200 types of banana in Indonesia. The utilization of bananas is influenced by the local culture, where in every 10 horticultural households, 5 of them plant bananas both as garden plants or field plants. This horticultural crop is expectantly being one of the actions to improve economic prosperity especially in rural areas. In maintaining the diversity of the growing bananas in rural areas, a geospatial approach to identify the vegetation is required. Remote sensing technology is one of the solutions to observe and to develop banana plants with one of the methods namely Object Based Image Analysis (OBIA). This method consists of segmentation, classification, and validation. In classification process, the OBIA method distinguishes objects not only based on pixel values but also on the basis of the shape, area, and texture around them. This research has proven that the classification using OBIA method is better than the traditional classification such as maximum likelihood classification method to identify banana plants. OBIA method can quickly identifies the vegetation and non-vegetation, also the regular plants and banana plants