ABSTRACT: Comparative metabolic and transcriptional analysis of a doubled diploid and its diploid citrus rootstock (C. junos cv. Ziyang xiangcheng) suggests its potential value for stress resistance improvement
Project description:Alkaline stress has serious negative effects on citrus production. Ziyang xiangcheng (Citrus junos Sieb. ex Tanaka) (Cj) has been reported to be a rootstock that is tolerant to alkaline stress and iron deficiency. Poncirus trifoliata (Poncirus trifoliata (L.) Raf.) (Pt), the most widely used rootstock in China, is sensitive to alkaline stress. To investigate the molecular mechanism underlying the tolerance of Cj to alkaline stress, next-generation sequencing was employed to profile the root transcriptomes and small RNAs of Cj and Pt seedlings which were cultured in nutrient solution with three gradient pH. This two-regulation level data set provides a system-level view of molecular events with precise resolution. The data suggest that the auxin pathway may play a central role in inhibitory effect of alkaline stress on root growth, and the regulation of auxin homeostasis under alkaline stress was important for citrus adapting to alkaline stress. Moreover, the JA pathway shown an opposite response to alkaline stress in Cj and Pt may contributes to the differentials of root system architecture and iron deficiency tolerance between Cj and Pt. The data set provides a wealth of genomic resources and new clues for further studying the mechanisms underlying Cj that resist alkaline stress.
Project description:Alkaline stress has serious negative effects on citrus production. Ziyang xiangcheng (Citrus junos Sieb. ex Tanaka) (Cj) has been reported to be a rootstock that is tolerant to alkaline stress and iron deficiency. Poncirus trifoliata (Poncirus trifoliata (L.) Raf.) (Pt), the most widely used rootstock in China, is sensitive to alkaline stress. To investigate the molecular mechanism underlying the tolerance of Cj to alkaline stress, next-generation sequencing was employed to profile the root transcriptomes and small RNAs of Cj and Pt seedlings which were cultured in nutrient solution with three gradient pH. This two-regulation level data set provides a system-level view of molecular events with precise resolution. The data suggest that the auxin pathway may play a central role in inhibitory effect of alkaline stress on root growth, and the regulation of auxin homeostasis under alkaline stress was important for citrus adapting to alkaline stress. Moreover, the JA pathway shown an opposite response to alkaline stress in Cj and Pt may contributes to the differentials of root system architecture and iron deficiency tolerance between Cj and Pt. The data set provides a wealth of genomic resources and new clues for further studying the mechanisms underlying Cj that resist alkaline stress.
Project description:Salt stress, especially saline-alkali stress, has seriously negative effect on citrus production. Ziyang xiangcheng (Citrus junos Sieb.) (Cj) has been reported as a saline-alkali stress and iron deficiency tolerant citrus rootstock. However, the molecular mechanism of its saline-alkali stress tolerance is still not clear. Two citrus rootstocks and one navel orange scion, Cj, Poncirus trifoliate (Poncirus trifoliata (L.) Raf.) (Pt) and ‘Lane Late’ navel orange (Citrus sinensis (L.) Osb.) (LL), were used in this study. The grafted materials Cj+LL and Pt+LL grown in calcareous soil were used to identify genes and pathways responsive to saline-alkali stress using RNA-seq. The seedlings of Cj and Pt grown in the solutions with different gradient pH value were used to perform a supplement experiment. Comprehensively analyzing the data of RNA-seq, physiology and biochemistry, agronomic traits and mineral elements of Cj+LL, Pt+LL, Cj and Pt, several candidate pathways and genes were identified to be highly regulated under saline-alkali stress. Here, we propose citrate is important for the tolerance to iron deficiency and the jasmonate (JA) biosynthesis and signal transduction pathway may play a crucial role in tolerance to saline-alkali stress in citrus by interacting with other plant hormones, calcium signaling, ROS scavenging system and lignin biosynthesis.
Project description:To investigate global genome expression changes caused by tetraploidization, we compared, by RNA-Seq analysis, the nuclear gene expression profiles of mature leaves of the diploid citrus rootstock and its doubled diploid. A total of 212 genes were differentially expressed between the diploid and doubled dipoid. In biological process category, DEGs were found to be highly related to stress-response functions, such as response to salt stress, to water, and to abscisic acid. In molecular function category, only two terms were overrepresented, namely, inorganic anion transmembrane transporter activity, inorganic phosphate transmembrane transporter activity.
Project description:Comprehensive analysis of transcriptomes reveals insight into the tolerance of Ziyang xiangcheng (Citrus junos Sieb. ex Tanaka) to alkaline stress
