ISSN 1021-4437, Russian Journal of Plant Physiology, 2016, Vol. 63, No. 5, pp. 709–717. © Pleiades Publishing, Ltd., 2016.
Physiological and Proteomic Analysis
of Mycorrhizal Pinus massoniana Inoculated with Lactarius insulsus
under Drought Stress
and X. Q. Wu
Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University,
Jiangsu Polytechnic College of Agriculture and Forestry, Jurong, China
Received November 18, 2015
Abstract—This study aimed to investigate physiological and protein expression alterations of mycorrhizal Pinus
massoniana Lamb. inoculated with Lactarius insulsus in response to drought stress. The P. massoniana seedlings
were inoculated with L. insulsus (Li group) and ectomycorrhized fungal-free filtrate (control, CK group),
respectively. After two and a half years, all the plants were exposed to a simulate drought condition without water
for 21 days. The soil relative water content (SRWC), wilting degree (WD) and wilting rate (WR) of the plants
were measured and root proteome was analyzed based on two-dimensional gel electrophoresis (2-DE), respec-
tively at four time points as 0, 7, 14 and 21 days during the whole drought period. Finally, the electrospray ion-
ization mass spectrometry (ESI-MS) was used to identify the differentially expressed proteins (DEPs) between
Li and CK groups. The SRWC was higher, while WR and WD were lower in Li group, compared with that in
CK group. Based on 2-DE and ESI-MS, 22 DEPs were identified between Li and CK groups during drought
stress. Among them, four proteins had the annotated information in relevant databases, including 1,4-benzo-
quinone reductase, PSCHI4, ribosomal protein L16 (RPL16) and AINTEGUMENTA-like (AIL) protein.
Mycorrhizal P. ma s s o n i a n a inoculated with L. insulsus achieved an enhanced drought resistance as compared to
the non-mycorrhizal, and the altered protein expressions such as 1,4-benzoquinone reductase, PSCHI4,
RPL16, and AIL might contribute to the improved resistance under drought stress.
Keywords: Pinus massoniana, Lactarius insulsus, drought stress, ectomycorrhiza, differentially expressed protein
Masson pine (Pinus massoniana Lamb.) is a native
species in China that considered as one of the most
ecologically and economically important coniferous
species for afforestation in southern China [1, 2].
Severe drought is an important factor that causes tre-
mendous growth loss and yields reduction of P. masso-
niana. . Tree roots are commonly colonized by
diverse microbes such as ectomycorrhiza (ECM) .
Reportedly, the ECM symbiosis could enhance shoot
biomass and root system quality of a plant, thus
increasing the survival of plants that transplanted to
the field . Under drought stress, the well-known
benefit of ECM for host plants is the improved nutri-
ent acquisition. Moreover, ectomycorrhizal symbiosis
could also facilitate to plant water uptake during
drought due to the increased aquaporin expression in
small seedlings . Pine species such as P. massoniana
could predominantly form ECM .
Lactarius insulsus is one of the most researched
pine ECM in China [8, 9]. A majority of previous
studies have focused on the optimal conditions for
ECM growth , and the effect of ECM on P. m a s s o-
niana biomass and nutrient acquisition . Recently,
several studies have investigated the effects of ECM on
P. m a s s o n i a n a under drought stress [11, 12]. However,
only the physiological changes are determined, such as
soil relative water content (SRWC), wilting rate (WR),
wilting degree (WD), malondialdehyde (MDA) con-
tent, and activities of superoxide dismutase (SOD),
peroxidase (POD), and nitrate reductase (NR). The
alterations at molecular level are scarce, especially at
Proteomics is frequently used to analyze biochem-
ical pathways and the complex response mechanisms
of plants in response to various abiotic stresses .
The article is published in the original.
Abbreviations: 2-DE—two-dimensional gel electrophoresis;
DEPs—differentially expressed proteins; DREBs—dehydration
responsive element binding proteins; ECM—ectomycorrhiza;
ESI-MS—electrospray ionization mass spectrometry; SRWC—
soil relative water content; WD—wilting degree; WR—wilting rate.