Response of Candidatus Liberibacter Asiaticus-Infected Citrus Plants to Bacillus amyloliquefaciens GJ1

                                       http://austinpublishinggroup.com/plant-biology/

CitrusHuanglongbing is considered to be one of the most devastating diseases threatening citrus production worldwide, and all cultivated citrus are suspceptible to the disease in different degree. The pathogen mainly are vectored by the Asian psyllid it is caused by three species of Gram-negative, α-proteobacteria, Candidatus Liberibacter spp. “Ca. L.asiaticus”, “Ca. L.africanus”, “Ca. L.americanus”. The disease can also be transmitted to healthy trees by grafting of diseased bud wood. Typical symptoms of Huanglongbing disease in leaves include shoot yellowing and blotchy mottled leaves, and in fruits express small, asymmetric, acidic, with many aboorted seeds. The callosedeposition occurs specifically in midribs of leaves. Disordered cambial tissue and massive accumulation of starch in phloem have also been reported. HLB has led to the devastating harm of citrus in more than 40 countries. HLB has not only decreased citrus production but also greatly increased production costs. HLB has reached epidemic proportions in Florida and has caused more than $4 billion in economic losses between 2005 to 2011.

Avariety of ways have been adopted to control HLB over the past few decades, for instance, heavy pruning inputting antibiotic agents inhibiting the LdtR gene by an inhibitor and screening the combination of stock and scion. However, the above mentioned techniques used for solving the problem of HLB present some limitations. Management of HLB to enable the continued economic production of citrus is the largest challenge ever faced by the citrus industry, and new control strategies are urgently needed.