Drought and salinity are the two major environmental constraints that severely affect global agricultural productivity. Plant-specific HD-Zip transcription factors are involved in plant growth, development and stress responses. In the present study, we explored the functional characteristics and regulation of a novel HD-Zip (I) gene from chickpea, CaHDZ12, in response to water-deficit and salt-stress conditions. Transgenic tobacco lines over-expressing CaHDZ12 exhibited improved tolerance to osmotic stresses and increased sensitivity to abscisic acid (ABA). Physiological compatibility of transgenic lines was found to be more robust compared to the wild-type plants under drought and salinity stress. Additionally, expression of several stress-responsive genes was significantly induced in CaHDZ12 transgenic plants. On the other hand, silencing of CaHDZ12 in chickpea resulted in increased sensitivity to salt and drought stresses. Analysis of different promoter deletion mutants identified CaWRKY70 transcription factor as a transcriptional regulator of CaHDZ12 expression. In vivo and in vitro interaction studies detected an association between CaWRKY70 and CaHDZ12 promoter during stress responses. Epigenetic modifications underlying histone acetylation at the CaHDZ12 promoter region play a significant role in stress-induced activation of this gene. Collectively, our study describes a crucial and unique mechanistic link between two distinct transcription factors in regulating plant adaptive stress response.

Attenuation in the activity of the negative regulators or the hyperactivity of plant innate immune receptors often causes ectopic defense activation manifested in severe growth retardation and spontaneous lesion formations, referred to as autoimmunity. In this review, we have described the cellular and molecular basis of the development of autoimmune responses for their useful applications in plant defense. Plants are exposed to diverse disease-causing pathogens, which bring infections by taking over the control on host immune machineries. To counter the challenges of evolving pathogenic races, plants recruit specific types of intracellular immune receptors that mostly belong to the family of polymorphic nucleotide-binding oligomerization domain-containing leucine-rich repeat (NLR) proteins. Upon recognition of effector molecules, NLR triggers hyperimmune signaling, which culminates in the form of a typical programmed cell death, designated hypersensitive response. Besides, few plant NLRs also guard certain host proteins known as 'guardee' that are modified by effector proteins. However, this fine-tuned innate immune system can be lopsided upon knock-out of the alleles that correspond to the host guardees, which mimick the presence of pathogen. The absence of pathogens causes inappropriate activation of the respective NLRs and results in the constitutive activation of plant defense and exhibiting autoimmunity. In plants, autoimmune mutants are readily scorable due to their dwarf phenotype and development of characteristic macroscopic disease lesions. Here, we summarize recent reports on autoimmune response in plants, how it is triggered, and phenotypic consequences associated with this phenomenon.

Background  Adherence to quality indicators and surveillance guidelines in the management of Barrett’s esophagus (BE) promotes high-quality, cost-effective care. The aims of this study were (1) to evaluate adherence to standardized classification (Prague Criteria) and systematic (four-quadrant) biopsy protocol, (2) to identify predictors of practice patterns, and (3) to assess adherence to surveillance guidelines for non-dysplastic BE (NDBE). Methods  This was a single-center retrospective study of esophagogastroduodenoscopy (EGD) performed for BE (June 2008 to December 2015). Patient demographics, procedure characteristics, and histology results were obtained from the procedure report-generating database and chart review. Adherence to Prague Criteria and systematic biopsies was based on operative report documentation. Multiple logistic regression analysis was performed to identify predictors of practice patterns. Guideline adherent surveillance EGD was defined as those performed within 6 months of the recommended 3- to 5-year interval. Results  In total, 397 patients (66.5 % male; mean age 60.1 ± 12.5 years) had an index EGD during the study period. Adherence to Prague Criteria and systematic biopsies was 27.4 % and 24.1 %, respectively. Endoscopists who performed therapeutic interventions for BE were more likely to use the Prague Criteria (OR: 3.16; 95 %CI: 1.47 – 6.82; P  < 0.01) than those who did not. Longer time in practice was positively associated with adherence to Prague Criteria (OR 1.07; 95 %CI: 1.02 – 1.12; P  < 0.01) but with a lower likelihood of performing systematic biopsies (OR 0.91; 95 %CI: 0.85 – 0.97; P  < 0.01). More than half (55.6 %) of patients with NDBE underwent surveillance EGD sooner (range 1 – 29 months) than the recommended interval. Conclusion  Adherence to quality indicators and surveillance guidelines in BE is low. Operator characteristics, including experience with endoscopic therapy for BE and time in practice predicted practice pattern. Future efforts are needed to reduce variability in practice and promote high-value care.

No abstract

No abstract