Shared and novel molecular responses of mandarin to drought.
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 beta-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.
Gimeno
Jacinta
J
Instituto De Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-CSIC, Camino de Vera s/n, Valencia, Spain.
Gadea
José
J
Forment
Javier
J
Pérez-Valle
Jorge
J
Santiago
Julia
J
Martínez-Godoy
María A
MA
Yenush
Lynne
L
Bellés
José M
JM
Brumós
Javier
J
Colmenero-Flores
José M
JM
Talón
Manuel
M
Serrano
Ramón
R
D000595:Amino Acid Sequence; D020346:Aquaporins / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002957:Citrus / Q000235:genetics* / Q000378:metabolism; D055864:Droughts; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D011887:Raffinose / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014867:Water / Q000494:pharmacology*
D020346:Aquaporins; D010940:Plant Proteins; D014157:Transcription Factors; D014867:Water; D011887:Raffinose