Growth Factors in Tomato Fruit 707 



The property we seek resides in pi-electron donors and atoms with 

 nonbonding electrons, singly or in combination, hence, in the indoles, 

 aryloxy compounds and other aromatic substances which have occu- 

 pied so much of our interest. 



It does not follow that all antioxidants (or electron donors) will 

 be growth promoters, or even regulators. The growth-promoting po- 

 tentialities of these compounds can only be realized if they are pre- 

 sented to the cell in suitable form. Antioxidants of different structure 

 which promote growth may operate through different limiting path- 

 ways, some acting as auxins, some as auxin-sparing agents, and others 

 as more uniquely localized protectants or cofactors. 



