Proteomic profile of Citrus grandis roots under long-term boron-deficiency revealed by iTRAQ

Eighty-six differentially abundant proteins were identified in Citrus grandis roots in response to boron-deficiency using the iTRAQ technique and possible mechanism underlying boron-deficiency tolerance of citrus plants was identified. Boron (B) is an essential element for plant growth and development and adequate B supply is an important determinant of good quality and high yield of crops. B-deficiency is a worldwide problem in agricultural production including citrus. However, little is known about the molecular mechanism of plant tolerance to B-deficiency. Using the iTRAQ technique, 86 differentially abundant proteins were identified from B-deficient Citrus grandis roots. The adaptive strategy of C. grandis roots under B-deficiency was summarized as follows: (1) enhancement of alternative splicing of mRNA and DNA methylation; (2) up-regulation of post-translation modification (PTM) and turnover of proteins; (3) reinforcement of cellular transport; (4) enhancement of antioxidant system and signal transduction. In general, these results increase our understanding of molecular mechanisms underlining the resistance of citrus plant under B-deficiency. Further studies should focus on how do roots perceive B deficiency in the rhizosphere and which pathway or proteins react to this adverse condition in the first place and then stimulates the downstream responses in Citrus plants.