Overexpression of Arabidopsis BBX21 enhanced phtosynthesis and alleviates photoinhibition in potato plants

GOMEZ-OCAMPO G, CROCCO C, MANTESE A, PLOSCHUK E, BOTTO J.

Congreso; Reunión Conjunta de Sociedades de Biociencias, SAIB; 2017

B-box (BBX) proteins are a class of zinc-finger transcriptionfactors containing a B-box which are highly conserved along green plant linages. Some members of BBX proteins are key factors in regulatory networks ofgrowth and developmental processes. BBX21 is a member of this family that promotes photomorphogenesis and dehydration tolerance, and inhibits shade avoidance in Arabidopsis thalianaseedlings. Regarding the relevance of BBX21 in light and ABA signaling and the null information of its role in adult plant development, we generated and studied the performance of Arabidopsis thalianaBBX21 heterologous overexpression in Solanum tuberosum (potato) plants under natural light conditions. The experiments were conducted in a greenhouse with controlled temperature cultivating three independent AtBBX21 overexpressing (BBX21-OE) lines and the non-transformant control.BBX21-OE potato adult plants have a more robust phenotype with higher tuber yield than non-transformant plants. In addition, BBX21-OE plants produce more chlorophyll and show higher photosynthesis rates and tolerance to photoinhibitionin than non-transformant. Biochemical studies demonstrated that BBX21-OE plants produced a larger amount of anthocyanins and total phenolic compounds that correlated with a higher expression of chalcone synthase gene involved in the early step of anthocyanin synthesis.Taking together, BBX21 appears as a potential candidate to improve crops plants through biotechnological approaches.