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"Lipopolysaccharide (LPS) is a major component of outer-membrane gram-negative bacteria, and it can act as aPathogen-Associated Molecular Pattern (PAMP) for perception of pathogens by plants. LPS can be recognized byplants, triggering certain plant defense-related responses, including callose deposition. This study investigated inductionof callose deposition by bacterial LPS in tobacco. Tobacco leaves were infiltrated with 400 μg/mL and 800 μg/mL LPSextracted from Pseudomonas syringae pv. tabaci (Pta) and Pseudomonas syringae pv. glycinea (Pgl) and incubated for24 h or 48 h. To detect callose deposition, tobacco leaves were cleared in lactophenol solution, stained with aniline blue,and visualized by fluorescence microscopy. Results showed that LPS from Pgl induced more callose deposition intobacco leaves than did that from Pta. In addition, a Pearson correlation test revealed that incubation period was themost significant factor in callose deposition, followed by the type of LPS bacteria. However, LPS concentration was notsignificantly corelated to callose deposition in tobacco leaves.Induksi Deposisi Callose pada Tanaman Tembakau (Nicotiana tabacum) oleh Lipopolisakrida BakteriPseudomonas syringae pv. tabaci dan Pseudomonas syringae pv. glycinea. Lipopolisakarida (LPS) adalah komponenutama permukaan sel bakteri gram negatif. LPS dapat berperan sebagai Pathogen-Associated Molecular Pattern(PAMP), yaitu molekul yang menjadi target pengenalan patogen oleh tanaman. Pengenalan LPS oleh tanaman dapatmenginduksi respon pertahanan tanaman, termasuk deposisi callose. Penelitian bertujuan untuk mengetahui induksideposisi callose pada tanaman tembakau oleh LPS bakteri yang diekstraksi dari bakteri Pseudomonas syringae pv.tabaci (Pta) dan P. syringae pv. glycinea (Pgl). Untuk pengamatan deposisi callose, daun tembakau diinfiltrasi LPS Ptadan Pgl, dengan konsentrasi 400 μg/ml dan 800 μg/ml, diinkubasi selama 24 dan 48 jam. Selanjutnya, klorofil daundiluruhkan menggunakan larutan laktofenol dan diwarnai dengan aniline blue. Deposisi callose diamati menggunakanmikroskop fluoresen. Hasil pengamatan menunjukkan LPS bakteri Pgl menginduksi deposisi callose lebih banyakdibandingkan LPS bakteri Pta. Lebih lanjut, berdasarkan uji korelasi pearson diketahui bahwa waktu inkubasi adalahfaktor yang berkorelasi paling signifikan terhadap deposisi callose, diikuti oleh jenis bakteri LPS. Namun, konsentrasiLPS tidak berkorelasi signifikan dengan deposisi callose pada daun tembakau."

"ABSTRAKTelah dilakukan penelitian yang bertujuan untuk menginduksi responspertahanan tanaman tembakau oleh lipopolisaakrida (LPS). LPS diekstraksi daribakteri Pseudomonas syringae pv. tabaci (Pta) dan P. syringae pv. glycinea (Pgl).Respons pertahanan tanaman yang diamati adalah deposisi callose dan ekspresigen terkait pertahanan (PAL, HIN 1 dan HSR 203J). Untuk pengamatan deposisicallose, daun tembakau diinfiltrasi dengan LPS Pta dan Pgl (400 µg/ml dan 800µg/ml) serta diinkubasi selama 24 dan 48 jam. Selanjutnya, klorofil daundiluruhkan menggunakan larutan laktofenol dan diwarnai dengan aniline blue.Deposisi callose diamati dibawah mikroskop fluoresensi. Hasil pengamatanmenunjukkan LPS bakteri Pgl menginduksi deposisi callose lebih banyakdibandingkan LPS bakteri Pta. Pengamatan ekspresi gen-gen terkait pertahanandilakukan pada daun tembakau yang diinfiltrasi dengan 400 µg/ml LPS bakteriPta and Pgl, serta diinkubasi selama 6 jam. Hasil RT-PCR terhadap dauntembakau menunjukkan LPS bakteri Pta dan Pgl mampu menginduksi ekspsresigen HIN 1, tetapi tidak mampu menginduksi ekspresi gen PAL dan HSR 203J.Gen HIN 1 terekspresi lebih kuat pada daun tembakau yang diinduksi oleh LPSbakteri Pgl daripada LPS Pta. Hasil penelitian mengindikasikan bahwa LPSbakteri Pgl menginduksi respons pertahanan daun tembakau lebih baik daripadaLPS bakteri Pta.

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AbstractThe aim of this study is to know the induction of tobacco defenseresponses by using lipopolysaccharides (LPS) which extracted from twophytopathogen, Pseudomonas syringae pv. tabaci (Pta) and P. syringae pv.glycinea (Pgl). The plant defense responses that observed are callose depositionand expression of defense-related genes (PAL, HIN 1 and HSR 203J). To detectcallose deposition, tobacco leaves were infiltrated with 400 µg/ml and 800 µg/mlLPS Pta and Pgl, then incubated for 24 or 48 hr. Tobacco leaves were cleared inlactophenol solution, stained with aniline blue, then visualized by fluorescencemicroscopy. The result showed that LPS from Pgl induced more callosedeposition than that from Pta in tobacco leaves. To investigate defense-relatedgenes expression, tobacco leaves were infiltrated with 400 µg/ml LPS extractedfrom Pta and Pgl, then incubated for 6 hr. Analysis of defense-related genesexpression were conducted by RT-PCR and visualized by electrophoresis on a1.8% agarose gel. The result showed LPS Pta and Pgl can induce expression ofHIN 1 gene in tobacco leaves, but can not induce the PAL and HSR 203J genes.The HIN 1 gene was highly expressed in tobacco leaves induced by LPS Pgl. Theresult indicates that tobacco could effectively recognize LPS of nonhost pathogenPgl but not in host pathogen Pta."