Centipedegrass [Eremochloa ophiuroides(Munro) Hack.], a member of the Panicoideae subfamily, is one of the most important warm-season turfgrasses originating from China. This grass has an extremely developed prostrate growth habit and has been widely used in transitional and warm climatic regions. To better understand the genetic basis of important biological characteristics, such as prostrate growth and seed yield, in warm-season turfgrasses, we present a high-quality reference genome for centipedegrass and use PacBio, BioNano, and Hi-C technologies to anchor the 867.43 Mb genome assembly into nine pseudochromosomes, with a scaffold N50 of 86.05 Mb and 36,572 annotated genes. Centipedegrass was most closely related to sorghum and diverged from their common ancestor ~16.8 Mya. We detected a novel chromosome reshuffling event in centipedegrass, namely, the nest chromosome fusion event in which fusion of chromosomes 8 and 10 of sorghum into chromosome 3 of centipedegrass likely occurred after the divergence of centipedegrass from sorghum. The typical prostrate growth trait in centipedegrass may be linked to the expansion of candidatePROSTRATE GROWTH 1(PROG1) genes on chromosome 2. Two orthologous genes ofOsPROG1,EoPROG1,andEoPROG2, were confirmed to increase the stem number and decrease the stem angle inArabidopsis. Collectively, our assembled reference genome of centipedegrass offers new knowledge and resources to dissect the genome evolution of Panicoideae and accelerate genome-assisted breeding and improvement of plant architecture in turf plants.
Zoysia matrella [L.] Merr. is one of the three most economically important Zoysia species due to its strong salt tolerance and wide application. However, the molecular mechanisms regulating salt tolerance in Z. matrella remain unknown. The protein disulfide isomerase ZmPDI of Z. matrella was obtained by salt stress screening with yeast cells, and its expression was significantly upregulated after salt stress. Based on the obtained ZmPDI overexpression transgenic Z. matrella plants, we carried out salt tolerance identification and found that ZmPDI can significantly enhance the salt tolerance of Z. matrella. Root samples of OX-ZmPDI transgenic and wild-type plants were collected at 0 and 24 h after salt treatments for RNA-seq and data-independent acquisition (DIA) proteome sequencing. Combined analysis of the transcriptome and proteome revealed that ZmPDI may enhance the salt tolerance of Z. matrella by regulating TUBB2, PXG4, PLDα2, PFK4, and 4CL1. This research presents the molecular regulatory mechanism of the ZmPDI gene in Z. matrella for resistance to salt stress and facilitates the use of molecular breeding to improve the salt tolerance of grasses.
23 September 2022 in Plant Physiology and Biochemistry