a group-1 grass pollen allergen influences the outcome of pollen competition in maize一组1草花粉过敏原的影响玉米花粉竞争的结果.pdfVIP

A Group-1 Grass Pollen Allergen Influences the Outcome of Pollen Competition in Maize 1¤a 1¤b 2 1 1 Elene R. Valdivia , Yajun Wu , Lian-Chao Li , Daniel J. Cosgrove , Andrew G. Stephenson * 1 Department of Biology and The Plant Physiology Graduate Program, The Pennsylvania State University, University Park, Pennsylvania, United States of America, 2 Proteomics and Mass Spectrometry Core Facility, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America Worldwide, 400 million people suffer from hay fever and seasonal asthma. The major causative agents of these allergies are pollen specific proteins called the group-1 grass pollen allergens. Although details of their antigenicity have been studied for 40 years with an eye towards immunotherapy, their function in the plant has drawn scant attention. Zea m 1 constitutes a class of abundant grass pollen allergens coded for by several genes that loosen the walls of grass cells, including the maize stigma and style. We have examined the impact of a transposon insertion into one of these genes (EXPB1, the most abundant isoform of Zea m 1) on the production of Zea m 1 protein, pollen viability, and pollen tube growth, both in vitro and in vivo. We also examined the effect of the insertional mutation on the competitive ability of the pollen by experimentally varying the sizes of the pollen load deposited onto stigmas using pollen from heterozygous plants and then screening the progeny for the presence of the transposon using PCR. We found that the insertional mutation reduced the levels of Zea m 1 in maize pollen, but had no effect on pollen viability, in vitro pollen tube growth or the proportion of progeny sired when small pollen loads are deposited onto stigmas. However, when large pollen loads are deposite