Exogenous Carbon Magnifies Mycorrhizal Effects on Growth Behaviour and Sucrose Metabolism in Trifoliate Orange

Arbuscular mycorrhizas (AMs) need the carbohydrates from host plants for its growth, whereas it is not clear whether exogenous carbon affects mycorrhizal roles. A two-chambered rootbox was divided into root + hyphae chamber and hyphae chamber (free of roots) by 37-μm nylon mesh, in which trifoliate orange (Poncirus trifoliata) seedlings and Funneliformis mosseae were applied into root + hyphae chamber, and exogenous 40 mmol/L fructose, glucose and sucrose was applied to hyphae chamber. Application of exogenous sugars dramatically elevated root mycorrhizal colonization. Sole arbuscular mycorrhizal fungi (AMF) inoculation significantly promoted plant growth and root morphology than non-AMF treatment. Mycorrhiza-improved plant growth and root modification could be enlarged by exogenous carbon, especially fructose. Exogenous carbon markedly increased root fructose, glucose and sucrose accumulation in mycorrhizal plants, especially sucrose. Exogenous fructose significantly reduced leaf and root sucrose synthase (SS) activity in synthesis direction and increased them in cleavage direction in AMF seedlings. Exogenous glucose and sucrose heavily elevated root SS activity of mycorrhizal seedlings in synthesis and cleavage direction and reduced leaf SS activity in synthesis direction. Leaf acid invertase (AI) and neutral invertase (NI) activities of mycorrhizal seedlings were decreased by exogenous carbon, except sucrose in NI. Exogenous fructose significantly increased root AI and NI activity in mycorrhizal plants. These results implied that mycorrhizal inoculation represented positive effects on plant growth, root morphology, and sucrose metabolism of trifoliate orange, which could be magnified further by exogenous carbon, especially fructose

Calculating the relative entropy of entanglement

We extend Vedral and Plenio's theorem (theorem 3 in Phys. Rev. A 57, 1619) to a more general case, and obtain the relative entropy of entanglement for a class of mixed states, this result can also follow from Rains' theorem 9 in Phys. Rev. A 60, 179.Comment: 2 pages, RevTex, an important reference adde

Mycorrhizal Fungi Regulate Root Responses and Leaf Physiological Activities in Trifoliate Orange

Plant responses to mycorrhization are mediated through secretion of certain signal molecules deposited in mycorrhizosphere in response to environmental stimuli. Responses of four arbuscular mycorrhizal fungi (AMF), namely Claroideoglomus etunicatum, Diversispora versiformis, Funneliformis mosseae, and Rhizoglomus intraradices on root morphology, lateral root (LR) number, and leaf carbohydrates, nitric oxide (NO), and calmodulin (CaM) changes were studied using trifoliate orange. Inoculation response of D. versiformis, F. mosseae, and R. intraradices registered significantly higher plant growth performance (plant height, stem diameter, leaf number, and shoot and root biomass), root morphological traits (total length, projected area, surface area, and volume), and LR number (first-, second-, third-, and forth-order), compared to un-inoculated response. Higher concentrations of CaM, NO, glucose, and fructose and lower sucrose level in leaves were observed in AMF-seedlings than in non-AMF seedlings. Correlation studies further revealed, root morphological traits and LR numbers were significantly negatively correlated with sucrose whereas positively correlated with glucose, fructose, NO, and CaM level in leaves. These results suggested, AMF-induced root modification is routed through sucrose cleavage and partly through changes in NO and CaM

Nitric oxide accelerates mycorrhizal effects on plant growth and root development of trifoliate orange

Arbuscular mycorrhizal fungi (AMF) actively colonize plant roots and thus enhance plant growth through different mechanisms. In the present study, trifoliate orange (Poncirus trifoliata) seedlings inoculated with Diversispora versiformis were subjected to 0 and 0.2 mmol/L sodium nitroprusside (SNP, a nitric oxide donor) treatments. After eight weeks, exogenous SNP considerably increased root mycorrhizal colonization by 25%, showing a positive stimulating effect of NO on mycorrhizal formation. Mycorrhizal inoculation significantly increased plant growth performance (height, stem diameter, leaf number and shoot and root dry weight) and root traits (length, projected area, surface area, volume and number of 2nd and 3rd order lateral roots) than non-mycorrhizal treatment and NO (exogenous SNP treatment) heavily strengthened the mycorrhizal effects. Moreover, NO and mycorrhization induced more fine root (0-0.5 cm) formation. There was an opposite changed trend in root sucrose and leaf and root glucose contents by SNP in AMF versus non-AMF seedlings. All these results implied that NO plays important roles in mycorrhizal formation and development and also accelerates mycorrhizal effects on plant growth and root development of trifoliate orange

Mycorrhiza and Common Mycorrhizal Network Regulate the Production of Signal Substances in Trifoliate Orange (Poncirus trifoliata)

Common mycorrhizal networks (CMNs) connecting two or more neighbouring plants are confirmed to transfer signals, whereas little information about CMNs effects on the signal substances production is known. In this study, a two-chambered rootbox separated by 37 µm nylon mesh was used to establish donor and receptor chambers. Two chambers both were planted with trifoliate orange (Poncirus trifoliata) and then only donor chamber inoculated with Diversispora versiformis, Paraglomus occultum and Rhizoglomus intraradices. The roots of the donor and receptor plants both were mycorrhizated suggesting that CMNs were established between donor and receptor seedlings. Moreover, the AMF association dramatically increased plant height, stem diameter, leaf numbers, and shoot and root biomass in both the donor and receptor seedlings. The AMF inoculation in the donor plants and the subsequent mycorrhizal colonization by CMNs in the receptor plants significantly increased root calmodulin (CaM) and salicylic acid (SA) concentrations, while considerably decreased root nitric oxide (NO) and jasmonic acid (JA) concentrations. This was accompanied by down-regulated expression of three JA synthetic genes (PtLOX, PtAOS and PtAOC), regardless of donor and receptor seedlings. These results thus suggest that CMNs between trifoliate orange seedlings manifestly promote plant growth and affect the production of signal substances

Calcium and Calmodulin Involve in Mycorrhizal and Root Development in Trifoliate Orange Colonized by Rhizophagus intraradices

A pot experiment was made to study effects of ethylene glycol tetraacetic acid (EGTA, an inhibitor of Ca2+) and trifluoperazine (TFP, an inhibitor of calmodulin (CaM) on mycorrhizal colonization, growth performance, and chlorophyll, sucrose and glucose concentrations of four-month-old trifoliate orange (Poncirus trifoliata) seedlings under mycorrhization with Rhizophagus intraradices. Exogenous EGTA and TFP notably inhibited root mycorrhizal colonization, and the addition of EGTA also decreased soil hyphal length. In general, EGTA treatment decreased but TFP increased easily extractable glomalin-related soil protein (EE-GRSP) and total GRSP (T-GRSP) concentrations. In addition, EGTA and TFP applications generally significantly inhibited growth performance (height, stem diameter, leaf number, and shoot and root biomass), root traits (total length, surface area, volume, and number of 1st, 2nd and 3rd order lateral root), and chlorophyll a,b and a+b concentrations, the mycorrhizal inoculation generally reversed the negative effects and markedly increased these variables, irrespective of whether the seedlings were applied by inhibitors or not. EGTA and TFP treatments generally inhibited sucrose and glucose levels of leaf and root, except that TFP application notably increased root glucose in AM and non-AM seedlings. AMF inoculation resulted in carbohydrate modification: decrease in leaf sucrose, increase in root sucrose and leaf glucose, as well increase in root glucose under no-inhibitor and EGTA conditions and decrease in root glucose under TFP. It suggests that Ca2+ and CaM were involved in mycorrhizal and root development in trifoliate orange

Investigation of a Side-polished Fiber MZI and Its Sensing Performance

A novel all-fiber Mach–Zehnder interferometer (MZI), which consists of lateral core fusion splicing of a short section of side-polished single mode fiber (SMF) between two SMFs was proposed and demonstrated. A simple fiber side-polished platform was built to control the side polished depth through a microscope. The sensitivity of the fiber MZI structure to the surrounding refractive index (RI) can be greatly improved with the increase of the side-polished depth, but has no effect on the temperature sensitivity. The sensor with a polished depth of 44.2 μm measured RI sensitivity up to -118.0 nm/RIU (RI unit) in the RI range from 1.333 to 1.387, which agrees well with simulation results by using the beam propagation method (BPM). In addition, the fiber MZI structure also can achieve simultaneous measurement of both RI and temperature. These results show its potential for use in-line fiber type sensing application