Chloroplast proteome response to drought stress and recovery in tomato (Solanum lycopersicum L.).
Drought is a major constraint for plant growth and crop productivity that is receiving an increased attention due to global climate changes. Chloroplasts act as environmental sensors, however, only partial information is available on stress-induced mechanisms within plastids. Here, we investigated the chloroplast response to a severe drought treatment and a subsequent recovery cycle in tomato through physiological, metabolite and proteomic analyses.



Under stress conditions, tomato plants showed stunted growth, and elevated levels of proline, abscisic acid (ABA) and late embryogenesis abundant gene transcript. Proteomics revealed that water deficit deeply affects chloroplast protein repertoire (31 differentially represented components), mainly involving energy-related functional species. Following the rewatering cycle, physiological parameters and metabolite levels indicated a recovery of tomato plant functions, while proteomics revealed a still ongoing adjustment of the chloroplast protein repertoire, which was even wider than during the drought phase (54 components differentially represented). Changes in gene expression of candidate genes and accumulation of ABA suggested the activation under stress of a specific chloroplast-to-nucleus (retrograde) signaling pathway and interconnection with the ABA-dependent network.



Our results give an original overview on the role of chloroplast as enviromental sensor by both coordinating the expression of nuclear-encoded plastid-localised proteins and mediating plant stress response. Although our data suggest the activation of a specific retrograde signaling pathway and interconnection with ABA signaling network in tomato, the involvement and fine regulation of such pathway need to be further investigated through the development and characterization of ad hoc designed plant mutants.
Institute of Biosciences and BioResources, National Research Council of Italy (CNR-IBBR), via Università 133, 80055, Portici, NA, Italy.
Rachele
R
Tamburino
Institute for the Animal Production System in the Mediterranean Environment, National Research Council of Italy (CNR-ISPAAM), via Argine 1085, 80147, Napoli, Italy.|Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, via Pansini, 80100, Napoli, Italy.
Monica
M
Vitale
Institute of Biosciences and BioResources, National Research Council of Italy (CNR-IBBR), via Università 133, 80055, Portici, NA, Italy.
Alessandra
A
Ruggiero
Institute for the Animal Production System in the Mediterranean Environment, National Research Council of Italy (CNR-ISPAAM), via Argine 1085, 80147, Napoli, Italy.
Mauro
M
Sassi
Institute of Biosciences and BioResources, National Research Council of Italy (CNR-IBBR), via Università 133, 80055, Portici, NA, Italy.
Lorenza
L
Sannino
Institute for the Animal Production System in the Mediterranean Environment, National Research Council of Italy (CNR-ISPAAM), via Argine 1085, 80147, Napoli, Italy.
Simona
S
Arena
Institute of Biosciences and BioResources, National Research Council of Italy (CNR-IBBR), via Università 133, 80055, Portici, NA, Italy.
Antonello
A
Costa
Institute of Biosciences and BioResources, National Research Council of Italy (CNR-IBBR), via Università 133, 80055, Portici, NA, Italy.
Giorgia
G
Batelli
Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, via Pansini, 80100, Napoli, Italy.|Center of Genetics Engineering (CEINGE) Biotecnologie Avanzate S.c. a R.l, via Pansini, 80100, Napoli, Italy.
Nicola
N
Zambrano
Institute for the Animal Production System in the Mediterranean Environment, National Research Council of Italy (CNR-ISPAAM), via Argine 1085, 80147, Napoli, Italy.
Andrea
A
Scaloni
Institute of Biosciences and BioResources, National Research Council of Italy (CNR-IBBR), via Università 133, 80055, Portici, NA, Italy.
Stefania
S
Grillo
Institute of Biosciences and BioResources, National Research Council of Italy (CNR-IBBR), via Università 133, 80055, Portici, NA, Italy. nscotti@unina.it.
Nunzia
0000-0002-7792-5955
N
Scotti
D000040:Abscisic Acid / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism* / Q000502:physiology; D003681:Dehydration; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D018551:Solanum lycopersicum / Q000378:metabolism / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011392:Proline / Q000378:metabolism
D010940:Plant Proteins; D000040:Abscisic Acid; D011392:Proline
Abscisic acid; Environmental sensor; Proline; Proteomic analysis; Retrograde signaling; Water deficit