Mycorrhizas alter sucrose and proline metabolism in trifoliate orange exposed to drought stress.
Arbuscular mycorrhizal fungi (AMF) can enhance drought tolerance in plants, whereas little is known regarding AMF contribution to sucrose and proline metabolisms under drought stress (DS). In this study, Funneliformis mosseae and Paraglomus occultum were inoculated into trifoliate orange (Poncirus trifoliata) under well watered and DS. Although the 71-days DS notably (P < 0.05) inhibited mycorrhizal colonization, AMF seedlings showed significantly (P < 0.05) higher plant growth performance and leaf relative water content, regardless of soil water status. AMF inoculation significantly (P < 0.05) increased leaf sucrose, glucose and fructose concentration under DS, accompanied with a significant increase of leaf sucrose phosphate synthase, neutral invertase, and net activity of sucrose-metabolized enzymes and a decrease in leaf acid invertase and sucrose synthase activity. AMF inoculation produced no change in leaf ornithine-δ-aminotransferase activity, but significantly (P < 0.05) increased leaf proline dehydrogenase activity and significantly (P < 0.05) decreased leaf both Δ1-pyrroline-5-carboxylate reductase and Δ1-pyrroline-5-carboxylate synthetase activity, resulting in lower proline accumulation in AMF plants under DS. Our results therefore suggest that AMF strongly altered leaf sucrose and proline metabolism through regulating sucrose- and proline-metabolized enzyme activities, which is important for osmotic adjustment of the host plant.
College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei 434025, China.|Institute of Root Biology, Yangtze University, Jingzhou, Hubei 434025, China.
Hui-Hui
HH
Wu
College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei 434025, China.|Institute of Root Biology, Yangtze University, Jingzhou, Hubei 434025, China.
Ying-Ning
YN
Zou
Brix' N Berries, Leduc, Alberta, Canada.
Mohammed Mahabubur
MM
Rahman
College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei 434025, China.|Institute of Root Biology, Yangtze University, Jingzhou, Hubei 434025, China.
Qiu-Dan
QD
Ni
College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei 434025, China.|Institute of Root Biology, Yangtze University, Jingzhou, Hubei 434025, China.|Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove 50003, Czech Republic.
Qiang-Sheng
QS
Wu
D050260:Carbohydrate Metabolism; D015169:Colony Count, Microbial; D055864:Droughts; D055137:Glomeromycota / Q000502:physiology; D038821:Mycorrhizae / Q000502:physiology*; D018515:Plant Leaves / Q000201:enzymology / Q000378:metabolism; D032104:Poncirus / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology*; D011392:Proline / Q000378:metabolism*; D036226:Seedlings / Q000378:metabolism; D013312:Stress, Physiological; D013395:Sucrose / Q000378:metabolism*; D014867:Water / Q000378:metabolism
D014867:Water; D013395:Sucrose; D011392:Proline