Decoding Pecan's Fungal Foe: A Genomic Insight into Colletotrichum plurivorum Isolate W-6.

Abstract

Pecan (Carya illinoinensis) is a world-renowned nut crop that is highly favored by consumers for its high content of healthy nutrients. For a long time, anthracnose has severely threatened the yield and quality of pecan, causing significant economic losses to the global pecan industry. Here, we report the 54.57-Mb gapless chromosome-level assembly of the pathogenic ascomycetes Colletotrichum plurivorum isolate W-6 from pecan plantations in Southeast China. Six of 12 chromosomes contain, at least, telomeric repeats (CCCTAA)n or (TTAGGG)n at one end. A total of 14,343 protein-coding genes were predicted. Pathogenicity- and virulence-related annotations revealed 137 to 4558 genes associated with the TCDB, PHI, Cyt_P450, DFVF, effector, and secretome databases, respectively. A comparative analysis of isolate W-6, together with 51 other Colletotrichum strains, reveled 13 genes unique to the Orchidearum complex to which isolate W-6 belongs, highlighting the major facilitator superfamily transporters. The detailed analyses of MFS transporters associated with secondary metabolite gene clusters in isolate W-6 led to the identification and protein structure analyses of two key virulence factor candidates in DHA1 subclass, prlG and azaK, which were reported as efflux transporters of antibiotics in other pathogenic fungi. The assembly and further functional investigation of two pathogenic genes identified here potentially provide important resources for better understanding the biology and lifestyle of Colletotrichum and pave the way for designing more efficient strategies to control anthracnose in pecan plantations.