title: Mycorrhizal association between the desert truffle Terfezia boudieri and Helianthemum sessiliflorum alters plant physiology and fitness to arid conditions.
abstract: The host plant Helianthemum sessiliflorum was inoculated with the mycorrhizal desert truffle Terfezia boudieri Chatin, and the subsequent effects of the ectomycorrhizal relationship on host physiology were determined. Diurnal measurements revealed that mycorrhizal (M) plants had higher rates of photosynthesis (35%), transpiration (18%), and night respiration (49%) than non-mycorrhizal (NM) plants. Consequently, M plants exhibited higher biomass accumulation, higher shoot-to-root ratios, and improved water use efficiency compared to NM plants. Total chlorophyll content was higher in M plants, and the ratio between chlorophyll a to chlorophyll b was altered in M plants. The increase in chlorophyll b content was significantly higher than the increase in chlorophyll a content (2.58- and 1.52-fold, respectively) compared to control. Calculation of the photosynthetic activation energy indicated lower energy requirements for CO(2) assimilation in M plants than in NM plants (48.62 and 61.56 kJ mol(-1), respectively). Continuous measurements of CO(2) exchange and transpiration in M plants versus NM plants provided a complete picture of the daily physiological differences brought on by the ectomycorrhizal relationships. The enhanced competence of M plants to withstand the harsh environmental conditions of the desert is discussed in view of the mycorrhizal-derived alterations in host physiology.
authors.affiliation: The Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
authors.forename: Tidhar
authors.initials: T
authors.lastname: Turgeman
authors.affiliation: The Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
authors.forename: Jiftach
authors.initials: J
authors.lastname: Ben Asher
authors.affiliation: Life Sciences Department, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
authors.forename: Nurit
authors.initials: N
authors.lastname: Roth-Bejerano
authors.affiliation: Life Sciences Department, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel.
authors.forename: Varda
authors.initials: V
authors.lastname: Kagan-Zur
authors.affiliation: Institute of Plant Sciences, the Volcani Center, Agricultural Research Organization, Bet-Dagan, 50250, Israel.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Kapulnik
authors.affiliation: The Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel. sitrit@bgu.ac.il.
authors.forename: Yaron
authors.initials: Y
authors.lastname: Sitrit
mesh_terms: D001203:Ascomycota / Q000254:growth & development*; D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D030601:Cistaceae / Q000737:chemistry / Q000254:growth & development / Q000382:microbiology* / Q000502:physiology*; D004734:Energy Metabolism; D010788:Photosynthesis; D018517:Plant Roots / Q000254:growth & development; D018520:Plant Shoots / Q000254:growth & development; D018526:Plant Transpiration; D013559:Symbiosis
chemical_list: D002734:Chlorophyll; D002245:Carbon Dioxide; C037184:chlorophyll b; D000077194:Chlorophyll A