AUTHOR=Law Jodi Woan-Fei , Ser Hooi-Leng , Khan Tahir M. , Chuah Lay-Hong , Pusparajah Priyia , Chan Kok-Gan , Goh Bey-Hing , Lee Learn-Han 

TITLE=The Potential of Streptomyces as Biocontrol Agents against the Rice Blast Fungus, Magnaporthe oryzae (Pyricularia oryzae)

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.00003

DOI=10.3389/fmicb.2017.00003

ISSN=1664-302X

ABSTRACT=<p>Rice is a staple food source for more than three billion people worldwide. However, rice is vulnerable to diseases, the most destructive among them being rice blast, which is caused by the fungus <italic>Magnaporthe oryzae</italic> (anamorph <italic>Pyricularia oryzae</italic>). This fungus attacks rice plants at all stages of development, causing annual losses of approximately 10–30% in various rice producing regions. Synthetic fungicides are often able to effectively control plant diseases, but some fungicides result in serious environmental and health problems. Therefore, there is growing interest in discovering and developing new, improved fungicides based on natural products as well as introducing alternative measures such as biocontrol agents to manage plant diseases. <italic>Streptomyce</italic>s bacteria appear to be promising biocontrol agents against a wide range of phytopathogenic fungi, which is not surprising given their ability to produce various bioactive compounds. This review provides insight into the biocontrol potential of <italic>Streptomyces</italic> against the rice blast fungus, <italic>M. oryzae</italic>. The ability of various S<italic>treptomyces</italic> spp. to act as biocontrol agents of rice blast disease has been studied by researchers under both laboratory and greenhouse/growth chamber conditions. Laboratory studies have shown that <italic>Streptomyces</italic> exhibit inhibitory activity against <italic>M. oryzae</italic>. In greenhouse studies, infected rice seedlings treated with <italic>Streptomyces</italic> resulted in up to 88.3% disease reduction of rice blast. Studies clearly show that <italic>Streptomyces</italic> spp. have the potential to be used as highly effective biocontrol agents against rice blast disease; however, the efficacy of any biocontrol agent may be affected by several factors including environmental conditions and methods of application. In order to fully exploit their potential, further studies on the isolation, formulation and application methods of <italic>Streptomyces</italic> along with field experiments are required to establish them as effective biocontrol agents.</p>