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41. Intracellular water and its relation to proteins and membranes
584
ANNUAL M E E T I N G ABSTRACTS
trical Monitoring of Cooling Treatments on nants of smooth muscle and connective tissue without a mucosal lining were identified in three of plants. D. S Fwrcs0N (Department of Biology, four segments frozen after 20% DMSO perfusion Mount Allison University, Sackville, New Brunsand in one of the seven segment~ frozen after 15% wick, Canada). DMSO perfusion. One of the four segmenls frozen Electrical measurements of impedance (Z) in alafter perfusion with 20% DMSO showed both falfa can apparently monitor water relations in the mucular and unorganized mucosaI elements. apoplast which seem in turn to be closely assoCoT~clusions. Under the experimental conditions, ciated with the ability of tile plant to resist cohl tim optimal concentration of DMSO lies in the d'~mage. Period of chilling, of light, at low tempera10% to 15% range, 20% being unsatisfactory. Mustures. ~md tre'~tmen~ with "alar" all tend to incle and connective tissues are more resistant to crease both Z and frost resistance. Alar does not freezing dam:~ge than is the intestinal mucosa. seem to alter the electric conductivib" of plasma 38. lsozyme Study of Freezing Rates and Cryo- menabr~mes nor their electro-osmotic efficiency. protective Additives. P. ,I. '.~']~ELNICK (Veterans Some Z measurements during cooling of potato Administration Hospital. Martinez, California). petioles, raspberry canes, and fucus thalli will be Comparative isozyme studies were made of the ef- presented as a basis for considering the role of fect of freezing rates and of crs'oprotective addi- •'~poplast, the channel for electric current, and the tives on a number of mouse, rat, guinea pig, and changes which may be induced in these during cold human tissues "rod tumors. Two sets of aliquot stress. blocks from e'lch specimen were pretreated with 41. IntraceHular Water and Its Relation to Pro. dimethyl sulfoxide (DMSO), glycerin, and polyteins and Me,ubranes. GILBEItT ,.N~. LI~'O (Movinyl pyrrolidone ( P V P ) . One set was frozen slowly lecular Biology Laboratory, Pennsyh'ania Hosand one set rapidly, together with untreated conpital. Philadelphia. Pennsylvania). trois. The aliquot blocks were homogenized and Recent experiment,tl evidence from nuclear magthe homogenates were subjected to electrophoresis netic resonance studies, from intracellular freezing in starch gels, all eight, aliquots from each specimen studies, and from sorption equilibrium studies inbeing inserted in parallel in the same gel. The gels dicate that the bulk of cell water is in a physical were sliced and were incubated with histochemical state different from that of water in a dilute salt methods for up to eight hydrolases and 15 oxida- solution. The facts are in harmony With or directly tive enzymes. For a number of enzymes pretreat- support the association-induction hypothesis, acmeat with c~'oprotective additives resulted in cording to which cell water exists as polarized mulmarkedly enhanced enzyme activity znd tJae ap- tflayer on the surface of cell proteins. Evidence pearance of additional isozyme bandr,, compared will be presented to show that water in this physito untreated controls, especially in the rapidly cal state within the cell and on the cell surface is frozen aliquots. Similar comparative studies of the able to maintain selected solute accumulation and tyo enzymes in blood serum revealed much less dif- permeability. These are functions which are conference; evidently active sites of enzymes in blood ventionally attributed respectively to metabolic serum remain more available for the histochemical pumps and lipid cell membrane. reactions after freezing, being unattached to cellu- 42. The Inheritance of Cohl Resistance in lar structure° In ti~ue sections previous studies Plants. C. O. GROGa,'," (CornelI University, Ithaca, (Melnick, P. J. Enzyme histochemist~5; in cryo.,New York). biology. In Crysurgery, R. W. Rand, A. P. Rinfret, The differential tolerance (resistance) of plant speand It. yon Leden, eds., pp. 52-77. Charles C cies and varieties to cold temperatures is well Thomas. Publisher. Springfield, Illinois, 1968) have known. Extensive information has been published shown that active sites of enzymes frequently be- on the physiological factors 'involved in tolerance come masked by freezing, especially by slow freez- to cold but agreement oa certain factors is not ening, and become unavailable for the histochemlcal tirely unanimous among investigators. T.he purpose reactions; pretreatment by c~,oprotective addi- of this paper is to consider the genetic contribution tives renders them freely available and readily to cold tolerance in plants. dem()v.,ztrable histodmm~caUy. The present isozyme Re~Astande in maize was found by several invess!,udies confirm t!mse findings; they also suggest tigators to be conditioned in cold tests by the endot-~vssibflities for fiirther exploration of cr3,ogenie sperm. Others argued that cold test, reaction was modalities. an interaction between genotype and cytoplasm 39. Membrane Stratetnre and the Influence of while still others found ex~idence for gone effects. Freezing. A. A. Br..~so~" (The Scripps Institute Few attempts were made to separate the influence of Oceanography, University of California, La of microorganisms and actual cold reaction. Winter dolla, California). hardine~ in small grains and forages has been 40. Plasma Membranes, Apoplast, and the Elee- a~eribed both to dominant and to rece~,~'e genes.
ANNUAL M E E T I N G ABSTRACTS
trical Monitoring of Cooling Treatments on nants of smooth muscle and connective tissue without a mucosal lining were identified in three of plants. D. S Fwrcs0N (Department of Biology, four segments frozen after 20% DMSO perfusion Mount Allison University, Sackville, New Brunsand in one of the seven segment~ frozen after 15% wick, Canada). DMSO perfusion. One of the four segmenls frozen Electrical measurements of impedance (Z) in alafter perfusion with 20% DMSO showed both falfa can apparently monitor water relations in the mucular and unorganized mucosaI elements. apoplast which seem in turn to be closely assoCoT~clusions. Under the experimental conditions, ciated with the ability of tile plant to resist cohl tim optimal concentration of DMSO lies in the d'~mage. Period of chilling, of light, at low tempera10% to 15% range, 20% being unsatisfactory. Mustures. ~md tre'~tmen~ with "alar" all tend to incle and connective tissues are more resistant to crease both Z and frost resistance. Alar does not freezing dam:~ge than is the intestinal mucosa. seem to alter the electric conductivib" of plasma 38. lsozyme Study of Freezing Rates and Cryo- menabr~mes nor their electro-osmotic efficiency. protective Additives. P. ,I. '.~']~ELNICK (Veterans Some Z measurements during cooling of potato Administration Hospital. Martinez, California). petioles, raspberry canes, and fucus thalli will be Comparative isozyme studies were made of the ef- presented as a basis for considering the role of fect of freezing rates and of crs'oprotective addi- •'~poplast, the channel for electric current, and the tives on a number of mouse, rat, guinea pig, and changes which may be induced in these during cold human tissues "rod tumors. Two sets of aliquot stress. blocks from e'lch specimen were pretreated with 41. IntraceHular Water and Its Relation to Pro. dimethyl sulfoxide (DMSO), glycerin, and polyteins and Me,ubranes. GILBEItT ,.N~. LI~'O (Movinyl pyrrolidone ( P V P ) . One set was frozen slowly lecular Biology Laboratory, Pennsyh'ania Hosand one set rapidly, together with untreated conpital. Philadelphia. Pennsylvania). trois. The aliquot blocks were homogenized and Recent experiment,tl evidence from nuclear magthe homogenates were subjected to electrophoresis netic resonance studies, from intracellular freezing in starch gels, all eight, aliquots from each specimen studies, and from sorption equilibrium studies inbeing inserted in parallel in the same gel. The gels dicate that the bulk of cell water is in a physical were sliced and were incubated with histochemical state different from that of water in a dilute salt methods for up to eight hydrolases and 15 oxida- solution. The facts are in harmony With or directly tive enzymes. For a number of enzymes pretreat- support the association-induction hypothesis, acmeat with c~'oprotective additives resulted in cording to which cell water exists as polarized mulmarkedly enhanced enzyme activity znd tJae ap- tflayer on the surface of cell proteins. Evidence pearance of additional isozyme bandr,, compared will be presented to show that water in this physito untreated controls, especially in the rapidly cal state within the cell and on the cell surface is frozen aliquots. Similar comparative studies of the able to maintain selected solute accumulation and tyo enzymes in blood serum revealed much less dif- permeability. These are functions which are conference; evidently active sites of enzymes in blood ventionally attributed respectively to metabolic serum remain more available for the histochemical pumps and lipid cell membrane. reactions after freezing, being unattached to cellu- 42. The Inheritance of Cohl Resistance in lar structure° In ti~ue sections previous studies Plants. C. O. GROGa,'," (CornelI University, Ithaca, (Melnick, P. J. Enzyme histochemist~5; in cryo.,New York). biology. In Crysurgery, R. W. Rand, A. P. Rinfret, The differential tolerance (resistance) of plant speand It. yon Leden, eds., pp. 52-77. Charles C cies and varieties to cold temperatures is well Thomas. Publisher. Springfield, Illinois, 1968) have known. Extensive information has been published shown that active sites of enzymes frequently be- on the physiological factors 'involved in tolerance come masked by freezing, especially by slow freez- to cold but agreement oa certain factors is not ening, and become unavailable for the histochemlcal tirely unanimous among investigators. T.he purpose reactions; pretreatment by c~,oprotective addi- of this paper is to consider the genetic contribution tives renders them freely available and readily to cold tolerance in plants. dem()v.,ztrable histodmm~caUy. The present isozyme Re~Astande in maize was found by several invess!,udies confirm t!mse findings; they also suggest tigators to be conditioned in cold tests by the endot-~vssibflities for fiirther exploration of cr3,ogenie sperm. Others argued that cold test, reaction was modalities. an interaction between genotype and cytoplasm 39. Membrane Stratetnre and the Influence of while still others found ex~idence for gone effects. Freezing. A. A. Br..~so~" (The Scripps Institute Few attempts were made to separate the influence of Oceanography, University of California, La of microorganisms and actual cold reaction. Winter dolla, California). hardine~ in small grains and forages has been 40. Plasma Membranes, Apoplast, and the Elee- a~eribed both to dominant and to rece~,~'e genes.