BIOCHEMICAL CHANGES IN SEED DORMANCY 201 



larger seeds. I am doubtful whether pollen grain would be of 

 help in this study, since they are too simple compared with 

 seeds. We would miss all the elements of interrelations. 



Mayer: I would like to defend myself against some of the 

 attacks made by Prof. Hestrin. I pointed out that we worked 

 with mashed up tissues, and that this fact limited the value of 

 our results. However, in this way we obtained indications which 

 will enable us to determine the specific parts of the tissue 

 involved. 



Halvorson: Is there any difference in the heat resistance of 

 the seed before and after germination? 



Klein : I am afraid this has not been tested. 



Goldwasser: I would like to suggest the use of the fluorescent 

 antibody technique to detect the site of enzyme formation, 

 provided you can prepare these enzymes in a reasonably pure 

 form. 



Koller: In regard to Prof. Hestrin's proposal for work on 

 homogeneous tissues, I would like to suggest fern spores. They 

 might be preferable to pollen grains, since they are activated by 

 light in the Red-Far Red system. 



Nachmony : I would like to suggest the use of Bryophyta as 

 suitable organisms for the biochemical study of these problems. 

 In these plants dormancy can be induced and broken by 

 photoperiodic treatment. The fact that almost every stage of the 

 life cycle, including young sporelings, is able to react to the 

 same treatment, may indicate that this ability is common to 

 almost all cells, thus making the whole organism nearly homo- 

 geneous in this respect. 



