Abiotic stress poses a great threat to plant growth and can lead to huge losses in yield.  Gene enolase2 (ENO2) is important in resistance to abiotic stress in various organisms.  ENO2 T-DNA insertion mutant (eno2^–) plants of Arabidopsis thaliana showed complete susceptibility to sodium chloride treatment when were analyzed either as whole plants or by measuring root growth during NaCl treatment.  Quantitative real-time RT-PCR (RT-qPCR) was performed to investigate the expression profile of ENO2 in response to NaCl stress in Arabidopsis.  The transcript level of ENO2 was rapidly elevated in 300 mmol L^–1 NaCl treatment.  ENO2 also responded to 300 mmol L^–1 NaCl treatment at the protein level.  To illuminate the mechanism underlying ENO2 resistance to salt at the transcriptional level, we studied the wild-type and eno2^– Arabidopsis lines that were treated with 300 mmol L^–1 NaCl for 18 h using 454 GS FLX, which resulted in an expressed sequence tag (EST) dataset.  A total of 961 up-regulated and 746 down-regulated differentially expressed genes (DEGs) were identified in the pairwise comparison WT-18 h:eno2^–-18 h.  The DEGs were identified and functionally annotated using the databases of Gene Ontology (GO) and the Kyoto encyclopedia of genes and genomes (KEGG).  The identified unigenes were subjected to GO analysis to determine biological, molecular, and cellular functions.  The biological process was enriched in a total of 20 GO terms, the cellular component was enriched in 13 GO terms, and the molecular function was enriched in 11 GO terms.  Using KEGG mapping, DEGs with pathway annotations contributed to 115 pathways.  The top 3 pathways based on a statistical analysis were biosynthesis of the secondary metabolites (KO01110), plant-pathogen interactions (KO04626), and plant hormone signal transduction (KO04075).  Based on these results, ENO2 contributes to increased resistance to abiotic stress.  In particular, ENO2 is involved in some of the metabolic stress response pathways in Arabidopsis.  Our work also demonstrates that this EST dataset will be a powerful resource for further studies of ENO2, such as functional analyses, investigations of biological roles, and molecular breeding.  Additionally, 3-phosphoglycerate kinase (PGK), 3-phosphoglycerate kinase 1 (PGK1), triosephosphate isomerase (TPI), and pyruvate kinase (PK) in glycolysis interactions with ENO2 were verified using the yeast two-hybrid experiment, and ENO2 may regulate the expression of PGK, PGK1, TPI, and PK.  Taken together, the results from this study reflects that ENO2 gene has an important role in the response to the high salt stress.

The germplasm resources for the S-type male sterility is rich in maize and it is resistant to Bipolaris maydis race T and CI, but the commercial application of S-type cytoplasmic male sterility (CMS-S) in maize hybrid industry is greatly compromised because of its common fertility instability. Currently, the existence of multiple minor effect loci in specific nuclear genetic backgrounds was considered as the molecular mechanism for this phenomenon. In the present study, we evaluated the fertility segregation of the different populations with the fertility instable material FIL-H in two environments of Beijing and Hainan, China. Our results indicated that the fertility instability of FIL-H was regulated by multiple genes, and the expression of these genes was sensitive to environmental factors. Using RNA sequencing (RNA-seq) technology, transcriptomes of the sterile plants and partially fertile plants resulted from the backcross of FIL-H×Jing 724 in Hainan were analyzed and 2 108 genes with different expression were identified, including 1 951 up-regulated and 157 down-regulated genes. The cluster analysis indicated that these differentially expressed genes (DEGs) might play roles in many biological processes, such as the energy production and conversion, carbohydrate metabolism and signal transduction. In addition, the pathway of the starch and sucrose metabolism was emphatically investigated to reveal the DEGs during the process of starch biosynthesis between sterile and partially fertile plants, which were related to the key catalytic enzymes, such as ADP-G pyrophosphorylase, starch synthase and starch branching enzyme. The up-regulation of these genes in the partially fertile plant may promote the starch accumulation in its pollen. Our data provide the important theoretical basis for the further exploration of the molecular mechanism for the fertility instability in CMS-S maize.

Jojoba (Simmondsia chinensis) is mainly distributed in desert, and the molecular mechanisms of jojoba in response to abiotic stress still remain elusive. In this paper, we cloned and characterized a SOD gene from jojoba named as ScMnSOD, and introduced into Arabidopsis to investigate its functions of responding to drought stress. The transgenic Arabidopsis showed an improvement in drought tolerance. Moreover, under a water deficit condition, the accumulation of reactive oxygen species (ROS) was remarkably decreased in the transgenic lines compared to the WT. Furthermore, the ScMnSOD promoter was cloned to the 5´-upstream of GUS coding region in a binary vector, and introduced into Arabidopsis. And results showed that ScMnSOD expression can be induced by drought, salt, ABA, and low temperature. In conclusion, ScMnSOD plays an important role in drought tolerance which is, at least partially, attributed to its role in ROS detoxification.