The expression patterns of threeVRNgenes in common wheat (Triticum aestivumL.) in response to vernalization

Abstract

Common wheat is a widely planted cereal in China, and vernalization is a crucial phase in wheat development. Although three major genes (VRN1, VRN2 and VRN3) are associated with the vernalization response, little is known about their expression profiles during wheat growth. In this study, we observed the spike differentiation process in spring wheat variety XC2 and winter wheat variety J841 and used qRT-PCR to analyze the expression patterns of three VRN genes in the leaves of these wheat varieties during development under vernalization versus non-vernalization treatment under long-day conditions. We also analyzed the expression patterns of VRN1 and VRN3 in the apical meristem. In both spring and winter wheat, the spikes remained at the single ridge state and did not differentiate under vernalization treatment. Spike differentiation completed one week earlier in XC2 spring wheat after vernalization treatment compared with non-vernalization conditions. Vernalization treatment significantly upregulated VRN1 and VRN3 expression in leaves under long-day conditions, whereas VRN2 expression was sharply reduced. The expression of VRN3 was low in shoot apical meristems, while VRN1 was highly expressed in shoot apical meristems when floral primordia began to differentiate and develop, suggesting that VRN1 functions independently in leaves and shoot apical meristems.