Raw Secondary Metabolites of Chitosan-enriched Pseudomonas fluorescens P60 to Control Corn Sheath Blight

Abstract

Corn is a strategic cereal with economic value and always face the corn sheath blight in the field. An alternative safely and environmentally friendly disease control is the use of biological agent Pseudomonas fluorescens P60 that produced raw secondary metabolites. This study aimed to test the effectiveness of chitosan enriched P. fluorescens P60 raw secondary metabolites against leaf blight and to determine the effect on the growth of maize. The research was conducted at the Laboratory of Plant Protection and Experimental Farm, Faculty of Agriculture, Jenderal Soedirman University. In vitro test used a completely randomized design and in planta test used a randomized block design consisted of four treatments and six replicates. The treatments consisted of control and the secondary metabolites of P. fluorescens P60 enriched with chitosan 1, 2, and 3%. Variables observed were inhibition ability, chitinase and protease analysis qualitatively, incubation period, disease intensity, infection rate, AUDPC, crop height, crop fresh weight, and root fresh weight. The results showed that the secondary metabolites of P. fluorescens P60 enriched with chitosan 3% was effective in inhibiting the growth of Rhizoctonia solani as 63.3%, produced chitinase and protease, and could control the disease by delaying the incubation period as 79.05%, lowering the disease intensity as 68.68%, lowering the infection rate as 100%, and lowering AUDPC as 83.32%. The secondary metabolites of P. fluorescens P60 enriched with chitosan 3% was effective in improving plant growth by increasing plant fresh weight as 33.9% and root fresh weight as 43.09% compared to control. Chitosan could be used for improving effectiveness of antagonistic bacteria raw secondary metabolites. The raw secondary metabolites of bacterial antagonists could be improved their effectiveness against plant diseases by enrichment of chitosan.

Effect of chitosan application time on seedlings of various rambutan varieties (Nephelium lappaceum L.)

“…Applying chitosan in the morning and afternoon increased the root length of the binjai and rapiah varieties, while the aceh variety treatment without chitosan application resulted in the highest root growth compared to the plants treated with chitosan. The hydrophilic properties of chitosan can help absorb water in soil, which is crucial for effective plant growth in the presence of external factors like water and nitrogen elements [16]. Root growth is influenced by water availability because roots will move according to water availability [17].…”

New Pseudomonas Bacterial Strains: Biological Activity and Characteristic Properties of Metabolites

“…Thus, P. fluorescens 2–79, which produces phenazine-1-carboxylic acid, P. aureofaciens 30–84, which produces 2-hydroxyphenazine-1-carboxylic acid and 2-hydroxyphenazine, and P. chlororaphis PCL1391, which produces pyocyanin, suppress Gaeumannomyces graminis var. tritici [ 7 , 8 , 9 ].…”

“…Lipopeptides of the syringomycin group contain amino acids, such as 2,4-diaminobutyric acid, and a C-terminal residue of chlorinated threonine. Masitolide A from the viscosin group, produced by the P. fluorescens SS101 strain, exhibits a direct antagonism against P. infestans and induces disease resistance in tomato crops [ 8 , 9 , 10 , 11 ].…”

“…Therefore, we consider the bacteria that produce them as potential agrobiotechnology objects—the basis for the development of biological crop protection products. Over the past two decades, the synthesis of antibiotics using rhizospheric bacteria has been one of the most successful and well-studied methods of biological control of various plant diseases [ 9 ].…”

Secondary metabolites of the granular form of Pseudomonas fluorescens P60 and its applications to control tomato bacterial wilt

“…In recent years, significant progress has been made in testing alternative control methods, particularly using microorganisms (biocontrol) for managing bacterial wilt (Mamphogoro et al 2020). One of them is using the antagonist bacteria Pseudomonas fluorescens Migula 1895 P60 (Soesanto et al 2021). The granule formulation of P. fluorescens is as effective as the granule bactericide in controlling the bacterial wilt of tomatoes (Soesanto et al 2019).…”