Deteksi Gen Ketahanan Hawar Daun Bakteri Xa21 pada Padi (Oryza sativa L.) Hitam dan Merah Lokal Indonesia

Beras berpigmen mulai popular dikonsumsi oleh masyarakat sebagai bahan pangan fungsional. Tetapi, terdapat faktor pembatas produksi beras berpigmen yaitu penyakit hawar daun bakteri yang disebabkan oleh Xanthomonas oryzae pv. Oryzae (Xoo). Penggunaan varietas tahan yang memiliki gen ketahanan Xa dinilai efektif untuk menanggulangi masalah penurunan hasil padi. Gen Xa ini antara lain terdiri dari gen Xa21. Penelitian ini bertujuan untuk mengetahui keberadaan gen ketahanan hawar daun bakteri Xa21 pada padi hitam kultivar Sembada Hitam, Cempo Ireng, Melik dan Hitam Toraja serta padi merah kultivar Aek sibondang, Merah Sumbawa, Segreng, dan Pari Eja di Indonesia. Metode penelitian meliputi isolasi genom padi, pengecekan hasil isolasi DNA dengan elektroforesis gel agarosa (0,8%), pengukuran konsentrasi dan kemurnian DNA, amplifikasi DNA primer pTA248, dan analisis data. Hasil penelitian ini mendeteksi keberadaan gen Xa21 pada semua kultivar padi hitam dan merah tersebut dengan dengan sifat tahan

Determination of allelopathic potential in mahogany (Swietenia macrophylla King) leaf litter using sandwich method

The sandwich method is a reliable screening bioassay that can be utilized to investigate allelopathic activity of leaf litter leachates. Screening the allelopathic potential of mahogany (Swietenia macrophylla King) leaf litter in plant–plant interaction using the sandwich bioassay method has not been reported. The research objectives were to determine and categorize allelopathic potential of S. macrophylla leaf litter using the sandwich bioassay method, and to determine specific activity (EC550). S. macrophylla leaf litter. The results showed that S. macrophylla leaf litter exhibited strong allelopathic activity when compared with 46 leaf litter species and was included in the top ten of allelopathic leaf litter species. Increasing S. macrophylla leaf litter concentration was concomitant with inhibition of radicle lettuce seedling growth compared with the control. According to the linear regression analysis, the effective concentration (EC50) of S. macrophylla was estimated to be 3.25 mg D.W. eq. mL-1 and was considered to have strong growth-inhibitory activity on lettuce radicle elongation. The results suggest the possibility of allelopathic potential of leaf litter in plant–plant interaction under S. macrophylla trees

Hd3a Florigen Recruits Different Proteins to Reveal Its Function in Plant Growth and Development

The nature of Hd3a protein in rice and its ortholog FT in Arabidopsis as a florigen has been proposed. However, molecular mechanism of its function still remains to be investigated. Therefore, it is important to search their interaction partners to better understand their signaling in flowering. As a long-distance signal that moves along leaf cells and the vascular system of leaves and stem and exerts its action in apical buds, it is important to determine the possible mediators of such common responses activated by Hd3a. To search Hd3a interactor, yeast two-hybrid screening have performed by using a cDNA library. A wide range of Hd3a interacting proteins involved in signaling were identified, including GF14c, OsKANADI and the BRI1 kinase domain interacting protein 116b (BIP116b). To reveal its function, Hd3a recruits different protein in plant developmental stage. It is possible that Hd3a and its partner(s) may form a platform for cross-talk between signal transduction pathways. Another homolog of Hd3a in many plants was identified and sugessted that Hd3a/FT has versatile role in plant development. This role depend on its partner and interaction to achieve its function. Our understanding in floral transition in rice would make for better crop management in future

Characterization of Streptomyces spp. Producing Indole-3-acetic acid as Biostimulant Agent

Twenty six isolates of Streptomyces spp. obtained from Cyperus rotundus L. rhizosphere were tested forability to produce indole-3-acetic acid (IAA) in yeast malt extract (YM) medium containing 2 mg/mL tryptophan.Screening of the isolates for ability to produce IAA was carried out by adding Salkowski reagent in bacteriaculture and was measured quantitatively by spectrophotometer at λ 530 nm. Thin Layer Chromatography (TLC)method was used to determine IAA. To ensure the IAA production in Streptomyces isolates, gene involved inIAA biosynthesis was detected by amplifying Tryptophan Monooxigenase (iaaM) gene. The study of the effectof tryptophan on the production of IAA was measured at different concentrations of tryptophan (0, 1, 2, 3,4, 5 mg/mL) in the bacterial culture. The result showed that there were two Streptomyces spp. isolates whichcould produce IAA, namely the isolates of Streptomyces sp. MS1 (125.48 μg/mL) and Streptomyces sp. BR27(104.13 μg/mL). The TLC result showed that the compound in both isolates was identifi ed to be IAA. Theamplifi cation results showed that iaaM gene was detected in both isolates. This results indicated that the IAMpathway is predicted involved in the biosynthesis of IAA in the selected isolates. Both of the isolates were ableto produce IAA after 24 h incubation and the highest production was at 120 h incubation with the concentrationof tryptophan was 2 mg/mL dan 1 mg/mL, respectively. Therefore, it is concluded that Streptomyces spp.isolates are able to produce IAA and potentially to be utilized as biostimulat agent. Keywords: Streptomyces spp., indole-3-acetic acid (IAA), indole-3-acetamide (IAM), Tryptophan Monooxigenasegene (iaaM

ANALISIS KANDUNGAN Gamma Aminobutyric Acid (GABA), FENOL TOTAL DAN AKTIVITAS ANTIOKSIDAN “BERAS KECAMBAH” KULTIVAR LOKAL (Oryza sativa L.) DI YOGYAKARTA

Rice is staple food in Indonesian and almost in all Asian. Germination is commonly method to increase nutritional content in grain and cereal. The aim of this research is to analyze gaba and total phenolic contents, and also antioxidant activity in germinated rice native cultivar from Yogyakarta. This research is also to determine the optimal condition in rice germination. Three native rice cultivars from Ngaglik Sleman Yogyakarta  used in this research, it were brown rice, red rice and black rice cultivars. Temperatures and soaking time variations used as treatments, rice without soaking treatment as controls.  The temperature variations was 28oC and 37oC and the  soaking time  was 6, 12, 18, and 12 hours. Three parameters GABA, total phenolic, and antioxidant activity was measured using spectrophotometric methods. The result of this research showed the cultivar that yield the highest GABA was black rice soaked in 37oC for 12 hour. It was 9,39 mg/100 g dry weight. Black rice without soaking treatment was the highest total phenolic content, it was 67,79 mg GAE/100 g dry weight with 7,91 ppm for IC50. The optimal condition was 37oC for 12 hour treated to Black rice that yield GABA 9,39 mg/100 g dry weight with total phenolic content and IC50 were 57,65 mg GAE/100 g dry weght  26,23 ppm, respectively

Potensi Bakteri Endofit Asal Tanaman Pisang Klutuk (Musa balbisiana Colla) Sebagai Pendukung Pertumbuhan Tanaman

AbstrakBakteri endofit yang terdapat di tanaman pisang Klutuk dan keterkaitannya dengan sifat ketahanan tanaman pisang Klutuk pada cekaman biotik dan abiotik belum dilaporkan dalam publikasi ilmiah. Sebanyak 93 isolat bakteri endofit telah diperoleh dari pisang Klutuk, tetapi belum diketahui kemampuannya sebagai pendukung pertumbuhan tanaman (PPT). Penelitian ini bertujuan untuk mengetahui karakter isolat-isolat bakteri endofit dari pisang Klutuk sebagai pendukung pertumbuhan tanaman. Kelompok bakteri Gram positif dan negatif ditentukan dengan metode pewarnaan Gram. Kemampuan memfiksasi nitrogen (N2), memproduksi asam indol asetat (AIA), dan antagonisme terhadap Fusarium oxysporum f. sp. cubense (Foc) diuji untuk mengetahui kemampuan isolat bakteri endofit sebagai pendukung pertumbuhan tanaman. Hasil penelitian menunjukkan bahwa 87,10% isolat bakteri endofit dari tanaman pisang Klutuk merupakan kelompok bakteri Gram negatif dan 82,80% (77 isolat bakteri) menunjukkan karakter tunggal atau ganda sebagai PPT. Di dalam kelompok isolat tersebut, terdapat berturut-turut 60, 38, dan 20 bakteri yang mampu memfiksasi N2, menghasilkan AIA, dan antagonisme terhadap Foc. Hasil pengujian ini menunjukkan bahwa bakteri endofit dari pisang Klutuk didominasi oleh bakteri kelompok Gram negatif yang memiliki kemampuan sebagai pendukung pertumbuhan tanaman.Abstract The role of endophytic bacteria on the biotic and abiotic resistance of Klutuk banana plants has never been reported. A total of 93 endophytic bacterial isolates were obtained from Klutuk banana plants in a previous study, but their potency as Plant Growth Promoting Bacteria (PGPB) is not elucidated. This study aims to characterize those 93 endophytic bacterial isolates. Gram staining was performed to differentiate between Gram-positive and negative bacteria among the isolates. The ability to fix nitrogen (N2), produce indole acetic acid (IAA) and antagonize Fusarium oxysporum f. sp. cubense (Foc) were also examined to determine their potency as PGPB. The results showed that 87.1% of the endophytic bacterial isolates were Gram-negative bacteria and 83.87% (78 bacterial isolates) had single or multiple traits of PGPB. Among the isolates, 60, 38, and 20 bacteria were able to fix N2, produce IAA, and antagonize Foc, respectively. The results indicated that the endophytic bacteria inhabiting Klutuk banana plant are dominated by Gram-negative PGPB

Functional Analysis of OsKANADI1, A Florigen Hd3a Interacting Protein in Rice (Oryza sativa L.)

OsKANADI1 is considered as a florigen Hd3a interacting protein. To study the function of OsKANADI1, the expression pattern of OsKANADI1 was performed by semiquantitative RT-PCR with various wild-type tissues in the floral transition stage. The results demonstrated that OsKANADI1 was expressed in all organs of wild-type plants, but was highest in roots and leaves. We hypothesize that OsKANADI1 is a transcription factor in rice because it contains a GARP domain and posses a nuclear localization signal. To determine whether OsKANADI1 encodes a nuclear protein, full-length OsKANADI1 fused to GFP was introduced into onion epidermis cells by particle bombardment. The result revealed that OsKANADI1 was localized in the nucleus, suggesting that OsKANADI1 may be a transcription factor. Functional analysis was carried out using a reverse genetics approach to generate gain of function mutant (overexpression) and knockdown mutant (RNAi). The results showed that suppression of OsKANADI1 by RNAi displayed branching and increasing tiller number in several lines. This phenotype resembles to the Hd3a overexpressed plants indicating they possibly function in similar pathway.Key words : OsKANADI1, Transcription factor, Hd3a interacting protein, Ric

Scanning Electron Microscopy Analysis of Tea’s Embryo Axis Explant Cultured on Murashige and Skoog Medium Containing 2,4-Dichlorophenoxyacetic acid

Camellia sinensis L. is an important crop in Indonesia as healthy beverage that contains several secondary metabolism compounds, such as polyphenols and catechins. Tissue culture including somatic embryogenesis and organogenesis has been used for propagating plant for various needs. In this present short-communication, scanning electron microscopic (SEM) analysis of tea was conducted and discussed. This study aimed to investigate surface ultrastructure of TRI2025 embryo axis tea clone cultured on Murashige and Skoog (MS) medium containing 2,4-Dichlorophenoxyacetic acid (2,4-D). The results revealed two different forms of explant’s development, i.e. somatic embryo and transitional form between somatic embryogenesis and organogenesis; or called by “Globular-like Structure” (GLS). Surface ultrastructure analysis of somatic embryo and GLS revealed respectively many stages of somatic embryo development i.e. globular, torpedo, and cotyledon stage, and leaf development form GLS regeneration.

Optimization of heat shock temperature and time on the transformation of pRGEB32 into Escherichia coli DH5α

Genome editing technique is one of the methods for studying the expression of gene, eliminating unfavorable traits or phenotypes and generating the new characters of species. The pRGEB32 plasmid is one of the vectors that used in genome editing with carrying the Cas9 gene, restriction site of sgRNA (single guide RNA) and specific promoters that can be expressed in plants. The first step in the genome editing process is inserting pRGEB32 into Escherichia coli for propagation. The large size of the plasmid molecule becomes a challenge to determine the right method in the transformation process. This study aims to determine the temperature and time of heat shock transformation of plasmid pRGEB32 into E. coli. The transformation of pRGEB32 into plasmids was carried out with variations in temperature and time, 42℃ (30 seconds and 60 seconds) and 55℃ (30 seconds and 60 seconds). The results showed that a heat shock temperature of 55℃ with a time of 60 seconds was the best temperature for the transformation of pRGEB32 into E. coli. This optimization of heat shock condition will increase the transformation efficiency, which is in the range of 3322-10.989 cfu/µg.

Optimization of qRT-PCR Annealing Temperature of WRKY45 Gene for Detection of Resistance Genes Against Xanthomonas oryzae pv. oryzae on Black Rice Cempo Ireng

Plant pathogens constrain the development of black rice farming. One of these pathogens is Xanthomonas oryzae pv. oryzae (Xoo), causing a bacterial leaf blight disease. The disease disrupts crop growth and reducing yields. Cempo ireng is a local pigmented rice cultivar from Yogyakarta, Indonesia, which is reported for its high resistance to Xoo. One of the rice resistance mechanisms to Xoo infection is a molecular defense employing plant resistance genes such as WRKY45. Comparing the expression of resistance-related genes of the resistant cultivar to the susceptible ones is needed to elucidate the resistance mechanism of the black rice to Xoo. For this purpose, the expression of WRKY45 gene at the level of mRNA can be performed using qRT-PCR. The success of qPCR analysis is greatly influenced by the accuracy of the annealing primer temperature of the corresponding gene. This study aimed to optimize the primer's annealing temperature for WRKY45 gene. The optimization was done by a temperature gradient PCR. Determination of the optimal annealing temperature was selected based on the profile of the amplification curve, melt curve, melt temperature and the Ct value obtained. The annealing temperature gradient used in this study was ranging from 52°C to 60°C. The results showed that the best annealing temperature for WRKY45 gene primers is 58.3°C based on the amplification curve, melt curve, melt peak and Ct value of 29.21