A novel <i>Meloidogyne graminicola</i> effector, MgGPP, is secreted into host cells and undergoes glycosylation in concert with proteolysis to suppress plant defenses and promote parasitism

<div><p>Plant pathogen effectors can recruit the host post-translational machinery to mediate their post-translational modification (PTM) and regulate their activity to facilitate parasitism, but few studies have focused on this phenomenon in the field of plant-parasitic nematodes. In this study, we show that the plant-parasitic nematode <i>Meloidogyne graminicola</i> has evolved a novel effector, MgGPP, that is exclusively expressed within the nematode subventral esophageal gland cells and up-regulated in the early parasitic stage of <i>M</i>. <i>graminicola</i>. The effector MgGPP plays a role in nematode parasitism. Transgenic rice lines expressing MgGPP become significantly more susceptible to <i>M</i>. <i>graminicola</i> infection than wild-type control plants, and conversely, <i>in planta</i>, the silencing of MgGPP through RNAi technology substantially increases the resistance of rice to <i>M</i>. <i>graminicola</i>. Significantly, we show that MgGPP is secreted into host plants and targeted to the ER, where the <i>N</i>-glycosylation and C-terminal proteolysis of MgGPP occur. C-terminal proteolysis promotes MgGPP to leave the ER, after which it is transported to the nucleus. In addition, <i>N</i>-glycosylation of MgGPP is required for suppressing the host response. The research data provide an intriguing example of <i>in planta</i> glycosylation in concert with proteolysis of a pathogen effector, which depict a novel mechanism by which parasitic nematodes could subjugate plant immunity and promote parasitism and may present a promising target for developing new strategies against nematode infections.</p></div

DataSheet1_Mining candidate genes for rice cadmium accumulation in the shoot through a genome-wide association study and transcriptomic analysis.xlsx

High cadmium (Cd) accumulation in rice is a serious threat to human health. The genetic mechanism of Cd accumulation in rice is highly complicated. To identify the low Cd accumulation in rice germplasm, investigate the genetic mechanism underlying Cd accumulation, and mine the elite genes of significant importance for rice breeding of low Cd accumulation varieties, we performed a genome-wide association study (GWAS) for rice Cd concentration in the shoot. The rice accessions were 315 diverse indica rice accessions selected from the 1568 rice accessions with 700,000 SNPs. Within the high rate of linkage disequilibrium (LD) decay, eight QTLs related to rice Cd accumulation were identified. Transcriptomic analysis showed there were 799 differentially expressed genes (DEGs) in the root and 857 DEGs in the shoot, which are probably considered to be the cause of the significant difference in Cd accumulation between high and low Cd accumulation varieties. In qCd11-1, we detected a crucial candidate gene, LOC_Os11g11050, which encodes an initiation factor, expressed differently in the root between the high and low Cd accumulation varieties. Furthermore, under Cd treatment, the expression levels of LOC_Os11g11050 significantly decreased in both the high and low Cd accumulation varieties. Sequence comparison and qRT-PCR revealed that there were indel sequences and base substitutions in the promoter region of LOC_Os11g11050 correlated with the LOC_Os11g11050 expression level, as well as the phenotype of Cd concentration differences in shoot between the high and low Cd accumulation accessions. LOC_Os11g11050 might play important roles in Cd accumulation. The results of our study provide valuable resources for low Cd accumulation in indica varieties and the candidate functional gene, as well as molecular mechanisms for Cd accumulation in indica rice. The genetic architecture underlying Cd accumulation in indica can be used for further applying the low Cd gene existing in indica for decreasing Cd accumulation in rice.</p