Background: Node is the central organ of transferring nutrients and ions in plants. Cadmium (Cd) induced crop pollution threatens the food safety. Breeding of low Cd accumulation cultivar is a chance to resolve this universal problem. This study was performed to identify tissue specific genes involved in Cd accumulation in different rice stem nodes. Panicle node and the first node under panicle (node I) were sampled in two rice cultivars: Xiangwanxian No. 12 (low Cd accumulation cultivar) and Yuzhenxiang (high Cd accumulation cultivar). RNA-seq analysis was performed to identify differentially expressed genes (DEGs) and microRNAs. Results: Xiangwanxian No. 12 had lower Cd concentration in panicle node, node I and grain compared with Yuzhenxiang, and node I had the highest Cd concentration in the two cultivars. RNA seq analysis identified 4535 DEGs and 70 miRNAs between the two cultivars. Most genesrelated to the “transporter activity”, such as OsIRT1, OsNramp5, OsVIT2, OsNRT1.5A, and OsABCC1, play roles in blocking the upward transport of Cd. Among the genes related to “response to stimulus”, we identified OsHSP70 and OsHSFA2d/B2c in Xiangwanxian No. 12, but not in Yuzhenxiang, were all down-regulated by Cd stimulus. The up-regulation of miRNAs (osa-miR528 and osa-miR408) in Xiangwanxian No. 12 played a potent role in lowering Cd accumulation via down regulating the expression of candidate genes, such as bZIP, ERF, MYB, SnRK1 and HSPs. Conclusions: Both panicle node and node I of Xiangwanxian No. 12 played a key role in blocking the upward transportation of Cd, while node I played a critical role in Yuzhenxiang. Distinct expression patterns of various transporter genes such as OsNRT1.5A, OsNramp5, OsIRT1, OsVIT2 and OsABCC1 resulted in differential Cd accumulation in different nodes. Likewise, distinct expression patterns of these transporter genes are likely responsible for the low Cd accumulation in Xiangwanxian No. 12 cultivar. MiRNAs drove multiple transcription factors, such as OsbZIPs, OsERFs, OsMYBs, to play a role in Cd stress response.

Many lncRNAs have been shown to play a vital role in aging processes. However, how lncRNAs regulate seed aging remains unknown. In this study, we performed whole transcriptome strand-specific RNA sequencing of samples from rice embryos, analyzed the differences in expression of rice seed lncRNAs before and after artificial aging treatment (AAT), and systematically screened 6002 rice lncRNAs. During the AAT period, the expression levels of most lncRNAs (454) were downregulated and only four were upregulated among the 458 differentially expressed lncRNAs (DELs). Cis- or trans-regulated target genes of the four upregulated lncRNAs were mainly related to base repair, while 454 downregulated lncRNAs were related to plant–pathogen interaction, plant hormones, energy metabolism, and secondary metabolism. The pathways of DEL target genes were similar with those of differentially expressed mRNAs (DEGs). A competing endogenous RNA (ceRNA) network composed of 34 lncRNAs, 24 microRNAs (miRNA), and 161 mRNAs was obtained. The cDNA sequence of lncRNA LNC_037529 was obtained by rapid amplification of cDNA ends (RACE) cloning with a total length of 1325 bp, a conserved 5′ end, and a non-conserved 3′ end. Together, our findings indicate that genome-wide selection for lncRNA downregulation was an important mechanism for rice seed aging. LncRNAs can be used as markers of seed aging in rice. These findings provide a future path to decipher the underlying mechanism associated with lncRNAs in seed aging.

Background: Node is the central organ of xylem to phloem transfer of nutrients and ions in plants. Cadmium (Cd)-induced crop pollution threatens food safety. Breeding cultivar with low Cd accumulation is a chance to resolve this universal problem. This study was performed to identify tissue specific genes involved in Cd accumulation in different rice stem nodes. Panicle node and the first node under panicle (node I) were sampled in two rice cultivars: Xiangwanxian No. 12 with low Cd accumulation and Yuzhenxiang with high Cd accumulation in the grains. RNA-seq analysis was performed to identify differentially expressed genes (DEGs) and microRNAs. Results: Xiangwanxian No. 12 had lower Cd concentration in panicle node, node I and grain compared with Yuzhenxiang, and node Ⅰ had the highest Cd concentration in the two cultivars. RNA seq analysis identified 4,535 differentially expressed genes and 70 miRNAs between the two cultivars. Most genes (OsIRT1, OsNramp5, OsVIT2, OsNRT1.5A, and OsABCC1) related to the “transporter activity” play roles in blocking the upward transport of Cd in the low Cd-accumulative cultivar. Among the genes related to “response to stimulus”, we identified OsHSP70 and OsHSFA2d/B2c in Xiangwanxian No. 12, but not in Yuzhenxiang, were all down-regulated by Cd stimulus. The up-regulation of miRNAs (osa-miR528 and osa-miR408) played a potent role in lowering Cd accumulation via down regulation of genes, such as bZIP, ERF, MYB, SnRK1 and HSPs in Xiangwanxian No. 12 cultivar. Conclusions: Both panicle node and node I of Xiangwanxian No. 12 played a key role in blocking the upward transportation of Cd, while node I played a critical role in Yuzhenxiang. Distinct expression patterns of various transporter genes such as OsNRT1.5A, OsNramp5, OsIRT1, OsVIT2 and OsABCC1 resulted in differential Cd accumulation in different nodes. Likewise, distinct expression patterns of these transporter genes are likely responsible for the low Cd accumulation in Xiangwanxian No. 12 cultivar. MiRNAs drove multiple transcription factors, such as OsbZIPs, OsERFs, OsMYBs, to play a role in stress response, which contribute to the response to Cd stress in rice.

Background: Node is the central organ of xylem to phloem transfer of nutrients and ions in plants. Cadmium (Cd)-induced crop pollution threatens food safety. Breeding cultivar with low Cd accumulation is a chance to resolve this universal problem. This study was performed to identify tissue specific genes involved in Cd accumulation in different rice stem nodes. Panicle node and the first node under panicle (node I) were sampled in two rice cultivars: Xiangwanxian No. 12 with low Cd accumulation and Yuzhenxiang with high Cd accumulation in the grains. RNA-seq analysis was performed to identify differentially expressed genes (DEGs) and microRNAs. Results: Xiangwanxian No. 12 had lower Cd concentration in panicle node, node I and grain compared with Yuzhenxiang , and node Ⅰ had the highest Cd concentration in the two cultivars. RNA seq analysis identified 4,535 differentially expressed genes and 70 miRNAs between the two cultivars. Most genes ( OsIRT1 , OsNramp5, OsVIT2 , OsNRT1.5A, and OsABCC1 ) related to the “transporter activity” blocked the transport of Cd up to panicle and accumulation in grains of low Cd-accumulative cultivar. Among the genes related to “response to stimulus”, we identified OsHSP70 and OsHSFA2d/B2c in “X”, but not in “y”, were all down-regulated by Cd stimulus. The up-regulation of miRNAs ( osa-miR528 and osa-miR408 ) played a potent role in lowering Cd accumulation via down regulation of genes, such as bZIP , ERF , MYB , SnRK1 and HSPs in Xiangwanxian No. 12 cultivar. Conclusions: Both panicle node and node I of Xiangwanxian No. 12 played a key role in blocking the upward transportation of Cd, while node I played a critical role in Yuzhenxiang . Distinct expression patterns of various transporter genes such as OsNRT1.5A, OsNramp5, OsIRT1, OsVIT2 and OsABCC1 resulted in differential Cd accumulation in different nodes. Likewise, distinct expression patterns of these transporter genes are likely responsible for the low Cd accumulation in Xiangwanxian No. 12 cultivar . MiRNAs drove multiple transcription factors, such as OsbZIPs, OsERFs, OsMYBs , to play a role in stress response, which contribute to the response to Cd stress in rice.

Background: Node is the central organ of transferring nutrients and ions in plants. Cadmium (Cd) induced crop pollution threatens the food safety. Breeding of low Cd accumulation cultivar is a chance to resolve this universal problem. This study was performed to identify tissue specific genes involved in Cd accumulation in different rice stem nodes. Panicle node and the first node under panicle (node I) were sampled in two rice cultivars: Xiangwanxian No. 12 (low Cd accumulation cultivar) and Yuzhenxiang (high Cd accumulation cultivar). RNA-seq analysis was performed to identify differentially expressed genes (DEGs) and microRNAs. Results: Xiangwanxian No. 12 had lower Cd concentration in panicle node, node I and grain compared with Yuzhenxiang , and node Ⅰ had the highest Cd concentration in the two cultivars. RNA seq analysis identified 4,535 DEGs and 70 miRNAs between the two cultivars. Most genes related to the “transporter activity”, such as OsIRT1 , OsNramp5, OsVIT2 , OsNRT1.5A, and OsABCC1 , play roles in blocking the upward transport of Cd. Among the genes related to “response to stimulus”, we identified OsHSP70 and OsHSFA2d/B2c in Xiangwanxian No. 12 , but not in Yuzhenxiang , were all down-regulated by Cd stimulus. The up-regulation of miRNAs ( osa-miR528 and osa-miR408 ) in Xiangwanxian No. 12 played a potent role in lowering Cd accumulation via down regulating the expression of candidate genes, such as bZIP , ERF , MYB , SnRK1 and HSPs . Conclusions: Both panicle node and node I of Xiangwanxian No. 12 played a key role in blocking the upward transportation of Cd, while node I played a critical role in Yuzhenxiang . Distinct expression patterns of various transporter genes such as OsNRT1.5A, OsNramp5, OsIRT1, OsVIT2 and OsABCC1 resulted in differential Cd accumulation in different nodes. Likewise, distinct expression patterns of these transporter genes are likely responsible for the low Cd accumulation in Xiangwanxian No. 12 cultivar . MiRNAs drove multiple transcription factors, such as OsbZIPs, OsERFs, OsMYBs , to play a role in Cd stress response.