ABSTRACT
The NAC (NAM, ATAF1/2, and CUC2) transcription factors are one of the largest families of transcription factors in plants and play an important role in plant development and the response to adversity. In this study, we cloned a new NAC gene, SlNAC10, from the halophyte Suaeda liaotungensis K. The gene has a total length of 1584 bp including a complete ORF of 1107 bp that encodes 369 amino acids. The SlNAC10-GFP fusion protein is located in the nucleus and SlNAC10 has a transcription activation structural domain at the C-terminus. We studied the expression characteristics of SlNAC10 and found that it was highest in the leaves of S. liaotungensis and induced by drought, salt, cold, and abscisic acid (ABA). To analyze the function of SlNAC10 in plants, we obtained SlNAC10 transgenic Arabidopsis. The growth characteristics and physiological indicators of transgenic Arabidopsis were measured under salt and drought stress. The transgenic Arabidopsis showed obvious advantages in the root length and survival rate; chlorophyll fluorescence levels; and the antioxidant enzyme superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities, and the proline content was higher than that of the wild-type (WT) Arabidopsis, whereas the relative electrolyte leakage and malondialdehyde (MDA) content were lower than those of the wild-type Arabidopsis. We explored the regulatory role of SlNAC10 on proline synthesis-related enzyme genes and found that SlNAC10 binds to the AtP5CS1, AtP5CS2, and AtP5CR promoters and regulates their downstream gene transcription. To sum up, SlNAC10 as a transcription factor improves salt and drought tolerance in plants possibly by regulating proline synthesis.
Subject(s)
Arabidopsis , Chenopodiaceae , Arabidopsis/metabolism , Chenopodiaceae/genetics , Chenopodiaceae/metabolism , Droughts , Gene Expression Regulation, Plant , Plant Proteins/genetics , Plant Proteins/metabolism , Plants, Genetically Modified/genetics , Proline/metabolism , Sodium Chloride/metabolism , Stress, Physiological/genetics , Transcription Factors/genetics , Transcription Factors/metabolismABSTRACT
BACKGROUND: Neonatal hypoglycemia is tightly related to adverse neurodevelopmental and brain injury outcomes. METHODS: A total of 195 infants who were born from diabetic mothers with a low blood glucose level (< 2.6 mM) within 0.5 h after birth were enrolled in this prospective cohort study. Of these, 157 infants who had neonatal hypoglycemia (group A) were followed up, and this group was further divided into A1 [blood glucose concentration (BGC) < 2.6 mM at < 2 h after birth], A2 (BGC < 2.6 mM at 2-24 h after birth), and A3 (BGC < 2.6 mM at > 24 h after birth). A total of 144 infants whose mothers had no high risk for gestational diabetes mellitus were followed up as the control group during the same period. The neurodevelopment of the infants was evaluated by the Gesell scoring method. RESULTS: The adaptability in the A2 and A3 subgroups was significantly lower than that in the control group (73.9 ± 6.6 vs. 87.9 ± 11.2; 71.5 ± 8.9 vs. 87.9 ± 11.2, respectively). There were significantly more mothers who used insulin during the perinatal period in A3 than in A1 and A2 (31% vs. 2%; 31% vs. 7.9%, respectively). The mothers of babies in subgroups A2 and A3 gained more weight than those of the control group (15.3 ± 1.9 kg vs. 11.1 ± 2.2 kg; 14.8 ± 2.6 kg vs. 11.1 ± 2.2 kg, respectively). CONCLUSIONS: Long and repeated neonatal hypoglycemia caused poor adaptability. The babies of mothers who used insulin or had a high weight gain during pregnancy were associated with severe or persistent neonatal hypoglycemia.
