scholarly journals Acetic Acid-Producing Endophyte Lysinibacillus fusiformis Orchestrates Jasmonic Acid Signaling and Contributes to Repression of Cadmium Uptake in Tomato Plants

2021 ◽  
Vol 12 ◽  
Author(s):  
Lin Zhu ◽  
Jiansheng Guo ◽  
Yujun Sun ◽  
Songhua Wang ◽  
Cheng Zhou

Diverse signaling pathways regulated by phytohormones are essential for the adaptation of plants to adverse environments. Root endophytic bacteria can manipulate hormone-related pathways to benefit their host plants under stress conditions, but the mechanisms underlying endophyte-mediated plant stress adaptation remain poorly discerned. Herein, the acetic acid-producing endophytic bacteria Lysinibacillus fusiformis Cr33 greatly reduced cadmium (Cd) accumulation in tomato plants. L. fusiformis led to a marked increase in jasmonic acid (JA) content and down-regulation of iron (Fe) uptake-related genes in Cd-exposed roots. Accordantly, acetic acid treatment considerably increased the JA content and inhibited root uptake of Cd uptake. In addition, the Cr33-inoculated roots displayed the increased availability of cell wall and rhizospheric Fe. Inoculation with Cr33 notably reduced the production of nitric oxide (NO) and suppressed Fe uptake systems in the Cd-treated roots, thereby contributing to hampering Cd absorption. Similar results were also observed for Cd-treated tomato plants in the presence of exogenous JA or acetic acid. However, chemical inhibition of JA biosynthesis greatly weakened the endophyte-alleviated Cd toxicity in the plants. Collectively, our findings indicated that the endophytic bacteria L. fusiformis effectively prevented Cd uptake in plants via the activation of acetic acid-mediated JA signaling pathways.

2021 ◽  
Vol 288 ◽  
pp. 110373
Author(s):  
Fei Ding ◽  
Chuang Wang ◽  
Ning Xu ◽  
Meiling Wang ◽  
Shuoxin Zhang

2020 ◽  
Vol 13 (2) ◽  
pp. 179-191
Author(s):  
Oktira Roka Aji ◽  
Iva Dita Lestari

AbstrakBakteri endofit hidup dalam suatu tanaman tanpa menyebabkan gangguan bagi tanaman yang berperan penting dalam menstimulasi pertumbuhan tanaman, yaitu dengan memproduksi fitohormon seperti asam absisat, asam indol asetat, dan sitokinin. Penelitian ini bertujuan untuk mengisolasi, menyeleksi, dan mengidentifikasi bakteri endofit yang terdapat pada daun, batang, dan akar tanaman jeruk nipis (Citrus aurantifolia). Isolat bakteri endofit diseleksi berdasarkan kemampuannya dalam menghasilkan asam indol asetat (AIA). Isolat bakteri endofit ditumbuhkan pada media nutrient broth (NB) yang ditambah dengan L-triptofan. Konsentrasi AIA dihitung dengan penambahan reagen salkowski dan diukur menggunakan spektrofotometer pada panjang gelombang 530 nm. Identifikasi bakteri endofit dilakukan dengan analisis uji biokimia. Isolat bakteri endofit yang berhasil diisolasi sebanyak 12 isolat, yaitu 4 isolat dari daun, 4 isolat dari batang, dan 4 isolat dari akar. Hasil pengamatan pada uji AIA menunjukkan bahwa semua isolat bakteri endofit dapat menghasilkan hormon AIA. Isolat yang menghasilkan konsentrasi hormon AIA tertinggi adalah isolat B2 (6,51 ppm). Isolat bakteri yang berhasil diidentifikasi berasal dari genus Enterobacter, Bacillus, Pseudomonas, dan Staphylococcus. Bakteri endofit yang dapat menghasilkan AIA berpotensi dikembangkan sebagai biofertilizer untuk meningkatkan produktivitas tanaman. Abstract Endophytic bacteria live inside plants without causing disruption to plants and play an important role in stimulating plant growth. This study aims to isolate endophytic bacteria from lime plant (Citrus aurantifolia) and characterize its ability to produce indole acetic acid (IAA). Bacterial isolates were grown on media supplemented with L-tryptophan as IAA precursor. The bacterial supernatant was mixed with salkowski reagents and then measured using a spectrophotometer at 530 nm. Bacterial identification was carried out using biochemical characteristic analysis. A total of 12 endophytic bacterial isolates were successfully isolated from leaves, stem and roots of plants. Quantitative test results showed that all isolates can produce IAA. The highest concentration of IAA was produced by B2 (6.51 ppm). Biochemical analysis indicated that the isolates were from the genus Enterobacter, Bacillus, Pseudomonas and Staphylococcus. Endhophytic bacteria that can produce IAA have the potential to be developed as biofertilizers to increase crop productivity.


2020 ◽  
Vol 21 (11) ◽  
Author(s):  
Vina Maulidia ◽  
Loekas Soesanto ◽  
Syamsuddin Syamsuddin ◽  
Khairan Khairan ◽  
Takahiro Hamaguchi ◽  
...  

Abstract. Maulidia V, Soesanto L, Syamsuddin, Khairan K, Hamaguchi T, Hasegawa K, Sriwati R. 2020. Secondary metabolites produced by endophytic bacteria against the Root-Knot Nematode (Meloidogyne sp.). Biodiversitas 21: 5270-5275. Endophytic bacteria live and colonize in plant tissues without causing disease to their plant host. Among several processes, these bacteria can produce secondary metabolites that can help in the defense of plant host against pathogens. This study aimed to identify endophytic bacteria as biocontrol agents against Meloidogyne sp. in tomato plants. Six endophytic bacteria candidates from the genus Pseudomonas, Arthrobacter, Bacillus, and Serratia were isolated from Solanum Lycopersicum, Psidium guajava, Pinus merkusii, Dendrocalamus asper, Albizia chinensis, and Theobroma cacao L, respectively. The average mortality of Meloidogyne sp. by endophytic bacteria was 70,27% to 95,46%. From these, B. thuringiensis AK08 produced compounds of the secondary metabolites such as flavonoid, phenol, tannins, terpenoids, steroids, saponins, and alkaloids. The best result of the average incubation period, number of galls in the root, number of nematodes at the root, and the number of nematodes in the soil on tomato plant were shown by B. thuringiensis. The major compounds in GC-MS analysis of B. thuringiensis were cholest-5-en-3-ol (3.beta.)-carbonochloridate (25.35%). Bacillus thuringiensis not only has rules as bio-insecticide but also has nematicidal effect.


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