Chloroplast Ubiquitin E3 Ligase SP1: Does It Really Function in Peroxisomes?

October 2017 d Vol. 175 d No. 2 On the Cover: The architecture of wheat inflorescence and its complexity are among the most important agronomic traits that influence yield. Wheat spikes vary considerably in the number of spikelets, which are specialized reproductive branches. The large and repetitive nature of the three homologous and highly similar subgenomes of wheat has impeded attempts at using genetic approaches to uncover beneficial alleles that can be utilized for yield improvement. In this issue, Wang et al. (pp. 746–757) used a population associative transcriptomic approach. They analyzed the transcriptomes of developing spikes in 90 wheat lines and correlated expression with variations in spike complexity traits. In combinationwith coexpressionnetworkanalysis, the identities of genes related to spike complexity were predicated. Further experimental studies identified regulatory genes, the expression ofwhich is associatedwith and influences spike complexity. Thus, the approach utilized in this study allows rapid identification of the genetic basis of important agronomic traits in crops with complex genomes. The cover image is a false-colored scanning electronmicrograph of awheat cvKN199 spike at the double ridge stage, a key stage determining the number of spikelets per spike. The spike meristem forms a limitednumber of lateral spikeletmeristems (yellow) per rachis node and a single terminal spikemeristem (yellow) at the distal end. Each spikelet meristem is indeterminate and will typically produce two to four fertile florets that produce seeds. Image by Yuange Wang.