RESUMO
Photosynthesis is the ultimate driving force behind world food production. Modern agricultural practices have done much to maximize the benefits of photosynthesis through better land management and intensive crop breeding. However, enhancement in grain production is becoming increasingly dependent on biotechnology with every improvement becoming more difficult to achieve. With several crop species nearing the physical limits of grain production, more attention will be given to methods that enable farmers to consistently attain maximum yields. These efforts focus in part on how plants respond to the biotic and abiotic stresses that can significantly reduce potential yields, including the study of plant signal transduction pathways related to stress responses. Strong evidence is emerging that these pathways share many similarities to classical mammalian receptor systems including tyrosine-kinase receptors and G protein-coupled receptors. Several putative receptor-like proteins have been identified in maize and provide vast opportunities for studying plant signal transduction mechanisms. The elucidation of plant signaling pathways combined with modern technologies will not only serve to push harvest yields closer to the maximum theoretical levels but may also provide opportunities for actually increasing the theoretical maximum.