Abstract
BackgroundqPE9–1/DEP1, encoding a G protein γ subunit, has multiple effects on plant architecture, grain size, and yield in rice. The qPE9–1 protein contains an N-terminal G gamma-like (GGL) domain, a putative transmembrane domain, and a C-terminal cysteine-rich domain. However, the roles of each domain remain unclear.ResultsIn the present study, we focused on the genetic effects of different domains of qPE9–1 in the regulation of grain length and weight. We generated a series of transgenic plants expressing different truncated qPE9–1 proteins through constitutive expression and clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 9 strategies. Phenotypic analysis indicated that the complete or long-tailed qPE9–1 contributed to the elongation of grains, while the GGL domain alone and short-tailed qPE9–1 led to short grains. The long C-terminus of qPE9–1 including two or three C-terminal von Willebrand factor type C domains effectively repressed the negative effects of the GGL domain on grain length and weight. qPE9–1-overexpressing lines in a Wuxianggeng 9 (carrying a qpe9–1 allele) background showed increased grain yield per plant, but lodging occurred in some years.ConclusionsManipulation of the C-terminal length of qPE9–1 through genetic engineering can be used to generate varieties with various grain lengths and weights according to different requirements in rice breeding. The genetic effects of qPE9–1/qpe9–1 are multidimensional, and breeders should take into account other factors including genetic backgrounds and planting conditions in the use of qPE9–1/qpe9–1.
Highlights
QPE9–1/DEP1, encoding a G protein γ subunit, has multiple effects on plant architecture, grain size, and yield in rice
Results qPE9–1 acts as a positive regulator of grain size in rice clustered regularly interspaced palindromic repeats (CRISPR)/Cas9 technology has been demonstrated to achieve efficient targeted mutagenesis in transgenic rice (Hu et al, 2016, Ma et al, 2016; Li et al, 2017; Lu et al, 2017), so was used here to disrupt qPE9–1
These two mutants lost most of the qPE9–1 protein, which covered part of the G gamma-like (GGL) domain and all C-terminal von Willebrand factor type C (VWFC) domains (Fig. 2a, b)
Summary
QPE9–1/DEP1, encoding a G protein γ subunit, has multiple effects on plant architecture, grain size, and yield in rice. The preference for rice varieties with different grain lengths varies among consumer groups (Li et al, 2004). Varieties with long, slender grains are preferred by consumers and cultivators in the USA and most Asian countries. Grain length affects 1000-grain weight, one of the yield components of rice, and subsequently determines rice productivity (Tan et al, 2000). More than 60 genes determining rice grain length and weight have been cloned, and several (2019) 12:5 signaling pathways including heterotrimeric G protein, the ubiquitin–proteasome pathway, the mitogen-activated protein kinase signaling pathway, phytohormones and transcriptional regulatory factors, have been investigated (Li et al, 2016b; Xu et al, 2016; Li et al, 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
