Comparison of cerato-platanin family protein BcSpl1 produced in Pichia pastoris and Escherichia coli

The Botrytis cinerea BcSpll protein is a member of the cerato-platanin family, and consists of 137 amino acids and two disulfide bridges. This protein induces the onset of necrosis in infiltrated plant hosts. Recombinant BcSpll proteins produced in Pichia pastoris (pBcSp11) and Escherichia coli (eBcSpI1) were initially compared regarding their abilities to induce necrosis and systemic acquired resistance (SAR). The pBcSpll and eBcSpll treatments led to the development of necrotic lesions on tomato leaves, and provided tomato plants with SAR to B. cinerea. The lesion area of leaves infiltrated with the BcSpll proteins decreased by 22.7% (pBcSp11) and 21.8% (eBcSpll). Additionally, eBcSp11 up-regulated the expression levels of some defense-related genes, including PR-la, prosystemin, PI I, and P1 II, as well as SIPK and TPIC1b, which encode two protein kinases. Furthermore, eBcSpll exhibited chitin-binding properties. Our data revealed that the E. coli expression system produces higher BcSpll yields than the P. pastoris system. This high-yield expression of BcSpll may be relevant for future large-scale applications of this elicitor to improve crop production. (C) 2017 Published by Elsevier Inc.