Transcriptional response of Citrus aurantifolia to infection by Citrus tristeza virus

Abstract

Changes in gene expression of Mexican lime plants in response to infection with a severe (T305) or a mild (T385) isolate of Citrus tristeza virus (CTV) were analyzed using a cDNA microarray containing 12,672 probes to 6875 different citrus genes. Statistically significant (P<0.01) expression changes of 334 genes were detected in response to infection with isolate T305, whereas infection with T385 induced no significant change. Induced genes included 145 without significant similarity with known sequences and 189 that were classified in seven functional categories. Genes related with response to stress and defense were the main category and included 28% of the genes induced. Selected transcription changes detected by microarray analysis were confirmed by quantitative real-time RT-PCR. Changes detected in the transcriptome upon infecting lime with T305 may be associated either with symptom expression, with a strain-specific defense mechanism, or with a general response to stress.

Selection of CTV-tolerant citrus hybrids for ornamental use

“…The practice of grafting can also promote faster flowering and consequently fruit production. With respect to spines, if this is considered undesirable, it can be prevented by using buds for propagation taken from branches related to more advanced vegetative generations, i.e., ontogenetically adult branches, on which spines are very sparse or absent in citrus in general [17,18]. Studies of compatibility between varieties for grafting and thorn characteristics need to be carried out to confirm this assertion.…”

The Complex Genetics of Citrus tristeza virus

“…These could be from either pathogenic or asymptomatic phenotypes to limited or complete plant resistance [5]. Although most of these mechanisms are still a mystery, new discoveries towards the understanding of the genetics of CTV movement in the plant, host-range, host resistance and pathogenicity have been reported recently [19,20,21,62,63,64].…”

“…Consequently, during the CTV-Citrus interaction there are multiple opportunities to generate disease. In fact, analysis of Mexican lime transcriptome using microarrays, after infection with a severe CTV isolate, showed altered expression of 334 genes and about half of them without significant similarity with other known sequences [63]. In this context, identifying a specific genetic determinant that is responsible for a specific disease symptom under field or glasshouse conditions could be a real challenge [20].…”

Molecular Virology and Pathogenicity of Citrus tristeza virus

“…However, determination of which of the viral products induce a specific symptomology is a complicated task. Analysis of Mexican lime transcriptome after infection with a severe CTV isolate showed altered expression of 334 genes and about half of them without significant similarity with other known sequences, thus indicating elevated complexity in the citrus-CTV interaction during symptoms development (Gandia et al, 2007). Many attempts have been made to develop rapid diagnostics for specific CTV syndromes.…”