## 4 Discussion
RM23191 of chromosomes 8 was commonly detected in 2016 and 2018 when QTL mapping was performed using WBPH resistant score, and also detected in 2020 when QTL mapping was performed using the results of HPLC analysis after WBPH inoculation, centering around this region, we searched for candidate genes for WBPH resistance. In this study, we performed QTL mapping of WBPH resistant gene through WBPH resistant score and HPLC analysis for 5 years, and searched candidate genes centered on RM23191 of commonly detected chromosome 8. Here, eight candidate genes were detected (_OsNox6_, _OsCCR_, _OsCM_, _OsOPR7_, _OsRR33_, _OsCLP1_, _OsBZIP66_, _OsDERF3_). In our research, we evaluated _OsCM_ (accession number MH752192) as a candidate gene which induces in response to WBPH resistant. _OsCM_ is a key enzyme in the shikimate pathway, which catalyzes a major step of converting chorismate into prephenate, a precursor of Phe and Tyr. The shikimate pathway provides aromatic compounds in prokaryotes, ascomycete fungi, apicomplexans and higher plants, but it is absent in mammals, which makes it an antibiotic target [44]. The conversion of chorismate to prephenate is a significoric shift reaction in the shikimate pathway [34; 45], which can also speed up the synthesis of a wide range of secondary metabolites through the synthesis of phenylalanine (Ph) and tyrosine (Tyr) [46]. Chorismate possesses a significant position in the shikimate pathway as it represents a main controlling linkage between primary and SMs synthesis in higher plants, which is controlled by _CM_. Furthermore, chorismate synthesized salicate through isochorismate synthase [47; 48], which is further involved in the synthesis of phylloquinone [49; 50]. Cochloquinone also known as luteoleersin [51] and the scientific name of basic skeleton is 17-methoxyochloquinone proposed by [PERSON] et al. 2009 [51]. It is a highly complex compound, and its biosynthesis is also very complex but here we will explain it briefly. Basically, this compound is composed of two basic units: one is a farnesyl group, which is also identical to oxadecalin, and the second unit is an acetogenin derivative of an aromatic compound, and we synthesized cochloquinone by cycloaddition of both the segments. Moreover, we established the mixed biosynthesis of cochloquinone through the introduction of a farnesyl unit onto an aromatic precursor whose secondary metal groups are provided by methionine which is produces in methionine biosynthesis pathway [52]. The first unit of cochloquinone is farnesyl pyrophosphate which is synthesized from tyrosine in the shikimate pathway. Tyrosine is the ultimate source of acetyl-CoA synthesis by a series of reactions like oxidative decarboxylation of pyruvate and tyrosine like other amino acids (phenylalanine, tryptophan and lysine) catabolism. Furthermore, acetyl-CoA goes under a series of reactions in isoprenoid pathway (mevalonate kinase pathway) and gives isopentenyl pyrophosphate (IPP) which further pair with another molecule of IPP and produce geranyl pyrophosphate (GPP). This GPP is the accepeter of another isoprene molecule and as a result produce farnesyl pyrophosphate (FPP) which is the precursor of all type of sesquiterpenes [53]. Here, it is important to mention that tyrosine and phenylalanine synthesis highly regulates by _CM_. The prenylation of acetogenin aromatic-derived nucleus leading to an intermediate complex and the decarboxylation-hydroxylation reaction converts it into another intermediate which is further converts to cochloquinone compound by the cyclization of the farnesyl chain [52]. This prenyl accepter primarily produced by polyketides but also it can be derived from tyrosine which is an evidence of _CM_ involvement in cochloquinone synthesis [54]. Moreover, quinone is the basic moiety of this compound which is also a product of the shikimate pathway. Chorismate mutase and shikimate pathway are also directly involved in another epi-cochlioquinone compound which is identical to cochlioquinone.