A semi-dominant mutation in a CC-NB-LRR-type protein leads to a short-root phenotype in rice

Abstract

The mechanisms of plant defense against pathogen attack in plant leaves have been extensively studied. However, our understanding of plant defense mechanisms in plant roots is still limited. In this study, a semi-dominant mutant nrtp1-D (necrotic root tip 1), with a short-root phenotype, was characterized in rice. Map-based cloning revealed that NRTP1 encoded a typical coiled-coil nucleotide binding leucine rich repeat (CC-NB-LRR) type protein and the mutation caused an amino acid substitution in the Nucleotide-Binding adaptor shared by Apaf1, certain R genes and CED4 (NB-ARC) domain, which may cause constitutive auto-activation of the NRTP1 protein. Gene expression analysis revealed that NRTP1 was preferentially expressed in rice roots. Expression of mutant nrtp1-D in tobacco leaves induced necrotic lesions, which indicated a common mechanism of plant defense response between leaves and roots. Transcriptome analysis revealed that many typical defense-response genes were differentially expressed in homozygous nrtp1-D. In addition, we also found differential expression of genes in pathways which had not previously been described as being associated with pathogen response. Histochemical analysis showed that the level of nitric oxide (NO), but not reactive oxygen species (ROS), was increased in homozygous nrtp1-D mutant roots. These results indicate that, in addition to the mechanism of defense response common to both roots and shoots, a novel pathway may also exist in rice roots, which does not operate in shoots.Electronic supplementary materialThe online version of this article (10.1186/s12284-018-0250-1) contains supplementary material, which is available to authorized users.

Identification and Characterization of Short Crown Root 8, a Temperature-Sensitive Mutant Associated with Crown Root Development in Rice

“…In the long-term evolutionary process, plants have established complex and diverse resistance response systems to resist the invasion of pathogens and insects. However, the abnormality of plant defense response disturbs the balance between plant growth and resistance response, resulting in a variety of abnormal phenotypes, such as lesion mimic leaf, spotted leaf, shorter root, hybrid weakness, and so on [ 15 , 38 , 39 , 40 , 41 , 42 , 43 ]. Therefore, plants must coordinate the balance between immune response and growth in a constantly changing environment.…”

“…Therefore, plants must coordinate the balance between immune response and growth in a constantly changing environment. The previous studies have shown that the proteins containing NB-ARC and LRR domains play key roles in the maintenance of the autoinhibited state, and the mutations of these domains activates plant defense responses [ 38 , 39 , 40 , 41 ]. NRTP1 encodes a typical coiled-coil nucleotide-binding leucine-rich repeat (CC-NB-LRR)-type protein, and its semi-dominant mutant showed defense response characteristics and exhibited shorter roots [ 39 ].…”

“…The previous studies have shown that the proteins containing NB-ARC and LRR domains play key roles in the maintenance of the autoinhibited state, and the mutations of these domains activates plant defense responses [ 38 , 39 , 40 , 41 ]. NRTP1 encodes a typical coiled-coil nucleotide-binding leucine-rich repeat (CC-NB-LRR)-type protein, and its semi-dominant mutant showed defense response characteristics and exhibited shorter roots [ 39 ]. Hwi1 comprises two loci—25L1 and 25L2—and both encode leucine-rich repeat receptor-like kinase (LRR–RLK), which is incompatible with Hwi2 derived from wild rice ( Oryza rufipogon ).…”

Genome-Wide Association Study (GWAS) of Mesocotyl Length for Direct Seeding in Rice

“…The NB-ARC domain acts as a nucleotide-binding pocket and hydrolyzes adenosine triphosphate (ATP) to induce conformational changes in NB-LRR proteins and plays an important role in controlling protein activity. It has been reported that it controls several brown planthopper (BPH) resistance genes that are also defense-related phenotypes [51,52]. According to the known function of Os01g0269800 in plant defense mechanisms, it is not clearly understood that the association of Os01g0269800 is involved in mesocotyl elongation.…”

Reappraisal of Spinach-based RNA Visualization in Plants

“…Agroinfiltration assay was performed in young leaves of N. benthamiana as previously described (Bruce et al, 2011;Yu et al, 2018). Briefly, 10 ml of A. tumefaciens GV3101 carrying pCVA/KK, pCVA/KSK or pCVB, a Cabbage leaf-curl geminivirus (CLCV)-based vector (Tang et al, 2010; were cultured to 0.6-0.8 OD600.…”