Transcriptome Analysis Shows Activation of Stress and Defense Responses by Silencing of Chlorophyll Biosynthetic Enzyme CHLI in Transgenic Tobacco

Abstract

In the present study, we have shown the transcriptional changes in a chlorosis model transgenic tobacco plant, i-amiCHLI, in which an artificial micro RNA is expressed in a chemically inducible manner to silence the expression of CHLI genes encoding a subunit of a chlorophyll biosynthetic enzyme. Comparison to the inducer-treated and untreated control non-transformants and untreated i-amiCHLI revealed that 3568 and 3582 genes were up- and down-regulated, respectively, in the inducer-treated i-amiCHLI plants. Gene Ontology enrichment analysis of these differentially expressed genes indicated the upregulation of the genes related to innate immune responses, and cell death pathways, and the downregulation of genes for photosynthesis, plastid organization, and primary and secondary metabolic pathways in the inducer-treated i-amiCHLI plants. The cell death in the chlorotic tissues with a preceding H2O2 production was observed in the inducer-treated i-amiCHLI plants, confirming the activation of the immune response. The involvement of activated innate immune response in the chlorosis development was supported by the comparative expression analysis between the two transgenic chlorosis model systems, i-amiCHLI and i-hpHSP90C, in which nuclear genes encoding different chloroplast proteins were similarly silenced.

Transcriptome and metabolome analyses reveal new insights into chlorophyll, photosynthesis, metal ion and phenylpropanoids related pathways during sugarcane ratoon chlorosis

“…Low chlorophyll content in chlorotic leaves decreased photosynthesis and fresh weight in Areca catechu and cucumber [5,9]. Chlorophyll biosynthesis plays a vital role in maintaining photosynthetic machinery [10,11]. Iron is an essential micronutrient for chlorophyll synthesis [12], and its deficiency is the most common cause of chlorosis [13].…”

Transcriptome and Metabolome Analyses Reveal an Insight of Chlorophyll, Photosynthesis, Metal Ion and Phenylpropanoids Related Pathways in Sugarcane Ratoon Chlorosis

“…Low chlorophyll content in chlorosis leaf decreases the photosynthetic rate and fresh weight [6,10]. Chlorophyll biosynthesis plays a vital role in maintaining photosynthetic machinery [11,12].…”