《Response of Organic Acids to Zinc Homeostasis in Zinc-Deficient and Zinc-Toxic Apple Rootstock Roots》.pdf

Pedosphere 22(6)：803—814，2012 ISSN 1002—0160／CN32—1315／P PEDOSPHERE ⑥ 2012SoilScienceSocietyofChina Published byElsevierB．V．and SciencePress wⅥ，、velsevierCom ／Iocate／pedosphere ResponseofOrganicAcidsto ZincHom eostasisin Zinc—Deficient and Zinc—ToxicAppleRootstock Roots LIU Di，LIU Ai—Hong，HE Chen，WANG Jin．HuaandWANG Yan—An StateKeyLaboratoryofCropBiology，CollegeofL Science，ShandongAgriculturalUniversity，Tai’an271018(China) (ReceivedMay6，2012；revisedSeptember21，2012) ABSTRACT ToelucidatethemechanismsoftolerancetozincfZn1deficiencyandZntoxicityintherootofappletrees，theapplerootstock Malushupehensis(Pamp．1RehdseedlingswereselectedtostudytheresponsesoforganicacidstoZnhomeostasisinrootsunderlow Znf0~tmolL一)，adequateZn(ascontrol，4p．molL一)andtoxicZn(100 molL一)treatments．ThedifferencesofZnconcentrations andaccumulationsintherootswerehighest，comparedwiththoseinthestemsandleaves，whenappleseedlingsweresubjectedto 1ow and toxicZntreatmentsfor1d．Theconcentrationsandaccumulationsofoxalicand malicacidsintherootsinthelow andtoxic Zntreatmentsincreasedbv2O％to60％ comparedwiththoseofthecontroltreatment．Significantlynegativecorrelationswerefound between thetotalZn concentrationsand the concentrati0nsofoxalic and malicacidsin therootsunder1 d oflow Zn treatment． However．contrary correlationswereofundforthetoxicZn treatment．M eanwhile，themaximum influxratesofZn under1ow and toxicZntreatmentsincreasedbv30％and20％．respectively,comparedwiththerateofthecontroItreatment．BothZndeficiencyand Zn toxicity increased theconcentrationsoforganicacidsin rootaftershort—timeZntreatment．which could resistZnstressthrough balanding Znhomeostasisin M ．hupehensisRehd． KeyWords： Malushupehensis(Pamp．)Rehd，Zncompartmentation，Zndeficiency，Zntoxicity，Znuptake Citation：Liu，D．，Liu，A．H．，He，C．，W ang，J．H．and W ang，Y A ．2012