In developing rice () endosperm, mRNAs of the major storage proteins, glutelin and prolamine, are transported and anchored to distinct subdomains of the cortical endoplasmic reticulum. RNA binding protein RBP-P binds to both glutelin and prolamine mRNAs, suggesting a role in some aspect of their RNA metabolism. Here, we show that rice lines expressing mutant RBP-P mislocalize both glutelin and prolamine mRNAs. Different mutant RBP-P proteins exhibited varying degrees of reduced RNA binding and/or protein-protein interaction properties, which may account for the mislocalization of storage protein RNAs. In addition, partial loss of RBP-P function conferred a broad phenotypic variation ranging from dwarfism, chlorophyll deficiency, and sterility to late flowering and low spikelet fertility. Transcriptome analysis highlighted the essential role of RBP-P in regulating storage protein genes and several essential biological processes during grain development. Overall, our data demonstrate the significant roles of RBP-P in glutelin and prolamine mRNA localization and in the regulation of genes important for plant growth and development through its RNA binding activity and cooperative regulation with interacting proteins.
The cultivated peanut Arachis hypogaea (AABB) is thought to have originated from the hybridization of Arachis duranensis (AA) and Arachis ipaënsis (BB) followed by spontaneous chromosome doubling. In this study, we cloned and analyzed chromosome markers from cultivated peanut and its wild relatives. A fluorescence in situ hybridization (FISH)-based karyotyping cocktail was developed with which to study the karyotypes and chromosome evolution of peanut and its wild relatives. Karyotypes were constructed in cultivated peanut and its two putative progenitors using our FISH-based karyotyping system. Comparative karyotyping analysis revealed that chromosome organization was highly conserved in cultivated peanut and its two putative progenitors, especially in the B genome chromosomes. However, variations existed between A. duranensis and the A genome chromosomes in cultivated peanut, especially for the distribution of the interstitial telomere repeats (ITRs). A search of additional A. duranensis varieties from different geographic regions revealed both numeric and positional variations of ITRs, which were similar to the variations in tetraploid peanut varieties. The results provide evidence for the origin of cultivated peanut from the two diploid ancestors, and also suggest that multiple hybridization events of A. ipaënsis with different varieties of A. duranensis may have occurred during the origination of peanut.
The transport and targeting of glutelin and prolamine mRNAs to distinct subdomains of the cortical endoplasmic reticulum is a model for mRNA localization in plants. This process requires a number of RNA-binding proteins (RBPs) that recognize and bind to mRNA cis-localization (zipcode) elements to form messenger ribonucleoprotein complexes, which then transport the RNAs to their destination sites at the cortical endoplasmic reticulum. Here, we present evidence that the rice (Oryza sativa) RNAbinding protein, RBP-L, like its interacting RBP-P partner, specifically binds to glutelin and prolamine zipcode RNA sequences and is required for proper mRNA localization in rice endosperm cells. A transfer DNA insertion in the 39 untranslated region resulted in reduced expression of the RBP-L gene to 10% to 25% of that in the wild-type. Reduced amounts of RBP-L caused partial mislocalization of glutelin and prolamine RNAs and conferred other general growth defects, including dwarfism, late flowering, and smaller seeds. Transcriptome analysis showed that RBP-L knockdown greatly affected the expression of prolamine family genes and several classes of transcription factors. Collectively, these results indicate that RBP-L, like RBP-P, is a key RBP involved in mRNA localization in rice endosperm cells. Moreover, distinct from RBP-P, RBP-L exhibits additional regulatory roles in development, either directly through its binding to corresponding RNAs or indirectly through its effect on transcription factors.
In rice (Oryza sativa) endosperm cells, mRNAs encoding glutelin and prolamine are translated on distinct cortical-endoplasmic reticulum (ER) subdomains (the cisternal-ER and protein body (PB)-ER), a process that facilitates targeting of their proteins to different endomembrane compartments. Although the cis-and trans-factors responsible for mRNA localization have been defined over the years, how these mRNAs are transported to the cortical ER has yet to be resolved. Here, we show that the two interacting glutelin zipcode RNA-binding proteins (RBPs), RBP-P and RBP-L, form a quaternary complex with the membrane fusion factors N-ethylmaleimide-sensitive factor (NSF) and the small GTPase Rab5a, enabling mRNA transport on endosomes. Direct interaction of RBP-L with Rab5a, between NSF and RBP-P, and between NSF and Rab5a were established. Biochemical and microscopic analyses confirmed the colocalization of these RBPs with NSF on Rab5a-positive endosomes that carry glutelin mRNAs. Analysis of a loss-of-function rab5a mutant showed that glutelin mRNA and
Rice mutant lines containing defective membrane trafficking Rab5 and Rab5-GEF mislocalize glutelin RNAs intracellularly, and export specific sets of RNAs that share functions and/or intracellular locations to extracellular paramural bodies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.