scholarly journals The effects of microcystin‐LR in Oryza sativa root cells: F‐actin as a new target of cyanobacterial toxicity

Plant Biology ◽  
2020 ◽  
Vol 22 (5) ◽  
pp. 839-849 ◽  
Author(s):  
D. Pappas ◽  
S. Gkelis ◽  
E. Panteris
2009 ◽  
Vol 31 (6) ◽  
pp. 1255-1262 ◽  
Author(s):  
Cristiane Elizabeth Costa de Macêdo ◽  
Veronique Van Sint Jan ◽  
Jean-Marie Kinet ◽  
Stanley Lutts

2020 ◽  
Author(s):  
D. Pappas ◽  
S. Gkelis ◽  
E. Panteris

ABSTRACTMicrocystins are toxins produced by cyanobacteria, notorious for negatively affecting a wide range of living organisms, among which several plant species. Although microtubules are a well-established target of microcystin toxicity, its effect on filamentous actin (F-actin) in plant cells has not been studied yet.The effects of microcystin-LR (MC-LR) and the extract of a microcystin-producing freshwater cyanobacterial strain (Microcystis flos-aquae TAU-MAC 1510) on the cytoskeleton (F-actin and microtubules) of Oryza sativa (rice) root cells, were studied by light, confocal, and transmission electron microscopy. Considering the role of F-actin in endomembrane system distribution, the endoplasmic reticulum and the Golgi apparatus in extract-treated cells were also examined.F-actin in both MC-LR- and extract-treated meristematic and differentiating root cells exhibited time-dependent alterations, ranging from disorientation and bundling to the formation of ring-like structures, eventually resulting to a collapse of the F-actin network at longer treatments. Disorganization and eventual depolymerization of microtubules, as well as abnormal chromatin condensation were observed following treatment with the extract, effects which could be attributed to microcystins and other bioactive compounds. Moreover, cell cycle progression was inhibited in extract-treated roots, specifically affecting the mitotic events. As a consequence of F-actin network disorganization, endoplasmic reticulum elements appeared stacked and diminished, while Golgi dictyosomes appeared aggregated.These results support that F-actin is a prominent target of MC-LR, both in pure form and as an extract ingredient. Endomembrane system alterations can also be attributed to the effects of cyanobacterial bioactive compounds (including microcystins) on F-actin cytoskeleton.


Author(s):  
M. Arif Hayat

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.


1970 ◽  
Vol 5 (3) ◽  
pp. 391-403
Author(s):  
Wiwik Winarti ◽  
Eva Sartini Bayu ◽  
Revandy Iskandar Damanik

Keragaan morfologi dan kandungan antosianin padi beras merah (Oryza sativa L.) pada Kecamatan Munte dan Kecamatan Payung di Kabupaten Karo. Penelitian ini bertujuan untuk mendapatkan informasi morfologi dan kandungan antosianin padi beras merah (Oryza sativa L.). Penelitian ini dimulai dari Juni 2017dan selesai pada Januari 2018 di kecamatan Munte dan Kecamatan Payung Kabupaten Karo.Metode survei deskriptif menggunakan panduan International Rice Research Institute (IRRI). Teknik penentuan lokasi secara sengaja dan pengamblan sampel secara kebetulan.Uji kandungan antosianin menggunakan metode analitik dengan menghomogenkan sampel. Hasil eksplorasi didapatkan 72 genotipe yang dibagi menjadi tiga lokasi lahan. Berdasaran uji kandungan antosianin didapatkan lahan A memiliki kandungan tertinggi yaitu 0,5 mg/100 g dan terendah yaitu lahan B 0,08 mg/100 g.


ENTOMON ◽  
2018 ◽  
Vol 43 (4) ◽  
pp. 257-262
Author(s):  
Atanu Seni ◽  
Bhimasen Naik

Experiments were carried out to assess some insecticide modules against major insect pests of rice. Each module consists of a basal application of carbofuran 3G @ 1 kg a.i ha-1 at 20 DAT and Rynaxypyr 20 SC @ 30 g a.i ha-1 at 45 DAT except untreated control. All modules differ with each other only in third treatment which was applied in 65 DAT. The third treatment includes: Imidacloprid 17.8 SL @ 27 g a.i ha-1, Pymetrozine 50 WG @ 150 g a.i ha-1, Triflumezopyrim 106 SC @ 27 g a.i ha-1, Buprofezin 25 SC @ 250 g a.i ha-1; Glamore (Imidacloprid 40+Ethiprole 40% w/w) 80 WG @ 100 g a.i. ha-1, Thiacloprid 24 SC @ 60 g a.i ha-1, Azadirachtin 0.03 EC @ 8 g a.i ha-1, Dinotefuran 20 SG@ 40 g a.i ha-1 and untreated control. All the treated plots recorded significantly lower percent of dead heart, white ear- head caused by stem borer and silver shoot caused by gall midge. Module with Pymetrozine 50 WG @ 150 g a.i ha-1 treated plot recorded significantly higher per cent reduction of plant hoppers (>80% over untreated control) and produced higher grain yield (50.75 qha-1) than the other modules. Among the different treated modules the maximum number of spiders was found in Azadirachtin 0.03 EC @ 8 g a.i ha-1 treated module plot followed by other treatments.


2012 ◽  
Vol 2 (11) ◽  
pp. 13-14
Author(s):  
R. ARULMOZHI R. ARULMOZHI ◽  
◽  
Dr. A. MUTHUSWAMY Dr. A. MUTHUSWAMY

2011 ◽  
Vol 16 (1) ◽  
Author(s):  
Ahadiyat Yugi Rahayu ◽  
Tri Harjoso

Tujuan dari penelitian ini adalah untuk mengetahui pengaruh aplikasi abu sekam terhadap kandungan prolin dan silikat daun serta kualitas hasil yaitu protein dan amilosa biji padi gogo dan hubungan korelasi antar keempat komponen tersebut pada kondisi pertanaman 80 persen kapasitas lapang pada skala pot. Penelitian dilakukan di polibag dalam screen house Fakultas Pertanian Unsoed dengan menggunakan rancangan acak kelompok pola faktorial dengan faktor varietas (Situ patenggang, Limboto, Towuti, Batutegi dan Aek sibundong) dan faktor abu sekam (0, 2, 4, 6 t/ha), diulang tiga kali. Hasil penelitian menunjukan bahwa pemberian abu sekam dosis 2−6 t/ha mampu meningkatkan kandungan silikat daun antara 18,49−29,43% dan menurunkan kandungan amilosa biji pada lima varietas sekitar 4,19−6,92%. Pemberian abu sekam dosis 2−6 t/ha mampu meningkatkan kandungan prolin daun antara 27,56−70,63% dan protein biji antara 2,35−16,71%. Antarvarietas menunjukan bahwa kandungan prolin tertinggi dihasilkan oleh varietas Batu tegi 18,58 persen dan protein biji pada varietas Situ patenggang 9,55%. Terdapat korelasi antar karakter fisiologis yaitu antara silikat-prolin (0,62) dan kandungan protein-amilosa biji (-0,78).


2017 ◽  
Author(s):  
Agung Sugiharto ◽  
Dwi Rahmawati ◽  
FNU Prayitno

Salah satu upaya untuk meningkatkan produksi dan mutu benih di lahan salin yaitu melalui penggunaan metode ratun dengan penambahan bakteri sintetik Synechoccocus sp. Penelitian ini bertujuan untuk mengetahui produksi dan mutu benih padi ratun yang tercekam salinitas dengan penambahan bakteri sintetik Synechoccocus sp. Penelitian dilaksanakan pada bulan Juli - Desember 2015 di Desa Suco, Kecamatan Mumbul Sari Jember dan Laboratorium Teknologi Benih Politeknik Negeri Jember. Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok Faktorial (RAK) dengan 2 faktor dan 3 ulangan. Faktor pertama adalah cekaman Salinitas (S) yang terdiri dari 5 taraf, S1 = tanpa cekaman (kontrol), S2 = cekaman salinitas 1000 ppm, S3 = cekaman salinitas 2000 ppm, S4 = cekaman salinitas 3000 ppm, S5 = cekaman salinitas 4000 ppm. Faktor kedua inokulasi bakteri sintetik Synechoccocus sp. (B), yang terdiri dari 2 taraf, B1 = tanpa inokulasi bakteri (kontrol), B2 = Inokulasi sintetik Synechoccocus sp. Data dianalisis menggunakan uji F (ANOVA) dan dilanjutkan dengan perhitungan Duncan’s Multiple Range Test (DMRT). Hasil penelitian menunjukan perlakuan salinitas 1000 ppm (S2) menghasilkan jumlah anakan ratun produktif tertinggi yaitu 19,33 anakan. Cl- mempunyai fungsi utama dalam reaksi fotosintesis sehingga cekaman salintas pada perlakuan 1000 ppm (S2) dapat ditoleran oleh tanaman padi varietas Ciherang pada fase vegetatif. Pemberian Bakteri (B) Synechococcus sp. mampu menghasilkan tunas ratun tertinggi pada fase vegetatif yaitu 40,10 cm. Interaksi dari dua perlakuan menunjukan hasil yang nyata pada parameter jumlah gabah bernas yaitu cekaman salinitas 4000 ppm dengan inokulasi bakteri (B2S5) menghasilkan gabah bernas yang paling tinggi sebesar 99,06 butir. Inokulasi tanaman dengan Synechococcus sp. mampu meningkatkan kandungan nitrogen dan kandungan klorofil dalam jaringan tanaman. Interaksi antara cekaman salinitas 1000 ppm dengan inokulasi bakteri (B2S2) menghasilkan produksi per Ha yang paling tinggi yaitu 1,389 ton dan potensi produksi per Ha tertinggi yaitu 1.66 ton/ha.


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