Responses of mycorrhizal jack pine (Pinus banksiana) seedlings to NaCl and boron

Abstract

In earlier studies, we established that mycorrhizal associations protect plants against salt stress. However, elevated boron levels are often present in saline soils and little is known about the effects of boron on salt resistance of mycorrhizal plants. In the present study, we inoculated jack pine (Pinus banksiana) seedlings with Hebeloma sp., Suillus tomentosus and Wilcoxina mikolae var. mikolae to study the effects of mycorrhizal associations on seedling responses to boron and salt. Seedlings were grown in the greenhouse and subjected to 60 mM NaCl, 2 mM H 3 BO 3 or 60 mM NaCl + 2 mM H 3 BO 3 treatments for 4 weeks. Dry weights, shoot:root ratios and chlorophyll concentrations were higher in inoculated seedlings for all treatments compared with the noninoculated plants. When applied with NaCl, B aggravated needle necrosis while reducing Cl concentrations in shoots of non-inoculated plants. Plants treated with 2 mM H 3 BO 3 + 60 mM NaCl had similar concentrations of Na and B to those that were treated separately with 60 mM NaCl and 2 mM H 3 BO 3 . Plants inoculated with mycorrhizal fungi had lower shoot Na concentrations compared with non-inoculated seedlings, but showed relatively little impact from elevated B concentrations.

Expression Analysis of Aquaporins from Desert Truffle Mycorrhizal Symbiosis Reveals a Fine-Tuned Regulation Under Drought

“…M associations may affect water transport by altering plant morphological characteristics (Calvo-Polanco et al 2008) and, possibly, through a direct contribution of the hyphal network to water flow (Marjanović and Nehls 2008). One of the common explanations of improved water uptake by M compared with NM plants (Boyd et al 1986) is the increased absorbing surface induced by hyphae growing in the soil, combined with the fungal capability to take up water from soils with a low Fig.…”

Responses of jack pine (Pinus banksiana) seedlings to root zone pH and calcium

“…is a native tree species of Canadian boreal forest, and is an early successional species found in sandy and nutrient-poor sites (Cayford et al, 1967). It is among the conifer tree species showing stunted growth in calcareous soils in southeastern British Columbia and western Alberta, Canada (Kishchuk, 2000) and one of the main tree species considered for the revegetation of the oil sands areas affected by high pH and Ca (Renault et al, 2000;Apostol and Zwiazek, 2004;Calvo Polanco et al, 2008). In the present study, we carried out two controlledenvironment experiments to examine the growth and physiological responses of jack pine seedlings to neutral and high root zone pH in the presence of different Ca concentrations.…”

Effects of pH on NaCl tolerance of American elm (Ulmus americana) seedlings inoculated with Hebeloma crustuliniforme and Laccaria bicolor

“…There was a trend in inoculated plants at lower pH for developing larger shoots and smaller roots, resulting in a somewhat larger shootroot ratios compared to non-inoculated plants. This growth response has been frequently reported in mycorrhizal plants (Marjanović et al 2005;Calvo-Polanco et al 2008a;Karst et al 2008). Since fungal inoculation had no effect on the shoot:root dry weight ratios at pH 9, this could suggest a lower degree of root colonization at the higher pH.…”