Shared and novel molecular responses of mandarin to drought

• Published in: Plant molecular biology 2009-07, Vol.70 (4), p.403-420
• Main Authors: Gimeno, Jacinta, Gadea, José, Forment, Javier, Pérez-Valle, Jorge, Santiago, Julia, Martínez-Godoy, María A, Yenush, Lynne, Bellés, José M, Brumós, Javier, Colmenero-Flores, José M, Talón, Manuel, Serrano, Ramón
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Aquaporins - genetics; Aquaporins - metabolism; Biochemistry; Biomedical and Life Sciences; Blotting, Western; Citrus - genetics; Citrus - metabolism; Citrus fruits; Drought; Drought resistance; Droughts; Ethylene; Gene Expression Profiling; Gene Expression Regulation, Plant - drug effects; Hydrogen peroxide; Life Sciences; Molecular Sequence Data; Oligonucleotide Array Sequence Analysis - methods; Plant biology; Plant Leaves - genetics; Plant Leaves - metabolism; Plant Pathology; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - genetics; Plant Roots - metabolism; Plant Sciences; Plant species; Proteins; Raffinose - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Roots; Sequence Homology, Amino Acid; Transcription Factors - genetics; Transcription Factors - metabolism; Trees; Water - pharmacology; Water stress
• ISSN: 0167-4412; 1573-5028
• DOI: 10.1007/s11103-009-9481-2

Drought is the most important stress experienced by citrus crops. A citrus cDNA microarray of about 6.000 genes has been utilized to identify transcriptomic responses of mandarin to water stress. As observed in other plant species challenged with drought stress, key genes for lysine catabolism, proline and raffinose synthesis, hydrogen peroxide reduction, vacuolar malate transport, RCI2 proteolipids and defence proteins such as osmotin, dehydrins and heat-shock proteins are induced in mandarin. Also, some aquaporin genes are repressed. The osmolyte raffinose could be detected in stressed roots while the dehydrin COR15 protein only accumulated in stressed leaves but not in roots. Novel drought responses in mandarin include the induction of genes encoding a new miraculin isoform, chloroplast β-carotene hydroxylase, oleoyl desaturase, ribosomal protein RPS13A and protein kinase CTR1. These results suggest that drought tolerance in citrus may benefit from inhibition of proteolysis, activation of zeaxanthin and linolenoyl synthesis, reinforcement of ribosomal structure and down-regulation of the ethylene response.