The Arabidopsis leucine-rich repeat receptor kinase MIK2/LRR-KISS connects cell wall integrity sensing, root growth and response to abiotic and biotic stresses

Plants actively perceive and respond to perturbations in their cell walls which arise during growth, biotic and abiotic stresses. However, few components involved in plant cell wall integrity sensing have been described to date. Using a reverse-genetic approach, we identified the Arabidopsis thaliana leucine-rich repeat receptor kinase MIK2 as an important regulator of cell wall damage responses triggered upon cellulose biosynthesis inhibition. Indeed, loss-of-function mik2 alleles are strongly affected in immune marker gene expression, jasmonic acid production and lignin deposition. MIK2 has both overlapping and distinct functions with THE1, a malectin-like receptor kinase previously proposed as cell wall integrity sensor. In addition, mik2 mutant plants exhibit enhanced leftward root skewing when grown on vertical plates. Notably, natural variation in MIK2 (also named LRR-KISS) has been correlated recently to mild salt stress tolerance, which we could confirm using our insertional alleles. Strikingly, both the increased root skewing and salt stress sensitivity phenotypes observed in the mik2 mutant are dependent on THE1. Finally, we found that MIK2 is required for resistance to the fungal root pathogen Fusarium oxysporum. Together, our data identify MIK2 as a novel component in cell wall integrity sensing and suggest that MIK2 is a nexus linking cell wall integrity sensing to growth and environmental cues

DETERMINATION OF MISCONCEPTIONS REGARDING "COMPOUNDS'' CHAPTER IN SECONDARY EDUCATION 9th GRADE BY TWO-TIER CONCEPTUAL UNDERSTANDING TEST

Bu çalışmada ortaöğretim 9. sınıf öğrencilerinin kimya dersi "Bileşikler" ünitesi ile ilgili kavram yanılgılarına sahip olup olmadıklarını ve sahip oldukları kavram yanılgıları varsa bu yanılgıların derecesini tespit edebilmek için iki aşamalı kavramsal anlama testini geliştirmek amaçlanmıştır. Çalışmada ayrıca geliştirilen bu test yoluyla öğrencilerin kavram yanılgılarının belirlenmesi hedeflenmiştir. Toplam 34 maddeden oluşan test İzmir ilinde bulunan ortaöğretim kurumlarında öğrenim görmekte olan ve konuyu bilen toplam 175 öğrenciye uygulanmıştır. Yapılan madde analizleri sonucunda testin güvenirliği, maddelerin güçlük ve ayırt edicilik indeksleri ve çeldirici fonksiyonları elde edilmiştir. Madde analizlerinin sonucunda iki aşamalı kavramsal anlama testinden 10 madde çıkarılmıştır. Testin güvenirlik katsayısı (Cronbach Alfa) 0.80 olarak bulunmuştur. Testin madde güçlük indeksleri 0.24-0.90 aralığında, ayırt edicilik indeksleri ise 0.22-0.50 aralığında bulunmuştur. Testte her bir maddeye verilen yanıtların incelenmesi sonucunda, ünite ile ilgili öğrencilerin bazı kavram yanılgılarına sahip oldukları belirlenmiştir. The aim of this study is to determine whether 9th grade students in secondary schools have misconceptions regarding ‘'compounds'' chapter and to develope a two-tier conceptual understanding test to be able to determine the degree of the misconceptions if there are any. Furthermore; this study aims determining the the misconceptions of the students by means of this test. The test, consisting of a total of 34 items, was carried out with 175 students familiar with the subject and receiving education in secondary schools in Izmir. As a result of item analyses made, the reliability of the test, the difficulty and distinctiveness indices and the distractor functions of the items were acquired. As a result of the analysis item two-tier conceptual understanding test 10 items were removed.The relaibility coefficient of the test (Cronbach Alfa) was found as 0.796. As a result of item analyses, the item difficulty indices were found to be between 0.24-0.90 and the item discrimination index were between 0.20-0.50. Some misconceptions about compounds chapter were determined after the analysis of the items in the tes

Role and Regulation of Osmolytes and ABA Interaction in Salt and Drought Stress Tolerance

Abiotic stress conditions lead to the defects in plant growth and development and also reduction in flowering and fertility. Under prolonged stresses, imminent death of the plants has been observed. To cope with such stress conditions, plants accumulate a wide variety of organic solutes called osmolytes. Osmolytes are accumulated in bacteria, lower, and higher plants as a response primarily to abiotic stress. They encompass amino acids such as proline, tertiary sulfonium, and quaternary ammonium compounds like beatines, sugars (trehalose), and polyhydric alcohols (mannitol, sorbitol, pinitol, etc.). Osmolytes are accumulated in the cytoplasm as well as in chloroplasts in certain cases for osmotic adjustment under stress conditions. This enables the plants to absorb water and survive under stress. Out of the many phytohormones that play diverse roles during abiotic stress, abscisic acid (ABA) is an important one and perceived by plants by a core signaling module. As an integral part of signal transduction during stress conditions, ABA and other hormones regulate not only stomatal closure, but also a wide array of gene expressions including osmolyte biosynthetic pathway genes. Many signal molecules like nitric oxide, carbon monoxide, and hydrogen sulfide also play a vital role in osmolyte biosynthesis. Osmolytes appear to have multiple functions during stress such as osmotic adjustment and scavenging of reactive oxygen species (ROS). Thus, generation of ROS and osmolyte accumulation are linked together. This review summarizes the role played by ABA in signal transduction, the role of hormones to regulate osmolyte biosynthesis, and various functions carried out by them

Molekulare und funktionelle Charakterisierung des Arabidopsis thaliana Response Regulators ARR18

The two-component signaling system evolved as an important sensing and responding mechanism in Arabidopsis thaliana, which consists of hybrid histidine kinases (AHKs), histidine phosphotransfer proteins (AHPs) and response regulators (ARRs) biochemically linked by a histidine to aspartate phosphorelay. In our work, several functional and molecular biological approaches were performed to characterize and understand the function of the B-type response regulator ARR18. In our study, ARR18 has been found to be an active transcription factor whose activity and homodimerization mainly depend on its phosphorylation state. Further investigations revealed that ARR18 is also able to form heteromers with bZIP63 and negatively influences the transcriptional activity of bZIP63 in a process that again depends on the ARR18 phosphorylation state. Moreover, extensive studies showed that ARR18 and bZIP63 function as antagonistic regulators in osmotic stress signaling in Arabidopsis thaliana. The results of our study reveal the importance of the phosphorylation state of the ARRs in controlling each signaling mechanism and the importance of non-TCS related proteins which, by direct interaction with TCS elements, add a new degree of diversity and complexity to the TCS signaling network.Das Zweikomponentensystem hat sich zu einem wichtigen Signal-Antwort-Mechanismus in Arabidopsis thaliana entwickelt und besteht aus Hybrid-Histidinkinasen (AHKs), Histidin Phosphotransferproteinen (AHPs) und Responseregulatoren (ARRs), welche biochemisch über einen Histidin zu Aspartat Phosphorelay miteinander in Verbindung stehen. In der vorliegenden Arbeit wurde die funktion des Response-reulators ARR18 durch verschiedene funktionale und molekularbiologische Ansätze näher characterisiert. Es konnte gezeigt werden, dass ARR18 ein aktiver Transkriptionsfaktor ist dessen Aktivität und Homodimerisierung hauptsächlich von seinem Phosphorylierungszustand abhängen. Weitere Untersuchungen zeigten, dass ARR18 auch Heterodimere mit bZIP63 bilden kann und dessen Transkriptionsaktivität negativ beeinflusst, was ebenfalls vom Phosphorylierungszustand von ARR18 abhängt. Des Weiteren wurde durch umfassende Untersuchungen gezeigt, dass ARR18 und bZIP63 antagonistische Regulatoren der osmotischen Stressantwort in Arabidopsis thaliana darstellen. Die Ergebnisse unserer Untersuchungen zeigen die Bedeutung des Phosphorylierungszustandes der ARR18 bei der Kontrolle jedes Signalmechanismus sowie die Bedeutung von Proteinen, die nicht zum Zweikomponentensystem gehören jedoch durch direkte Interaktion mit dessen Elementen diesem ein neues Ausmaß an Diversität und Komplexität verleihen

Nail cSCC eSupplemental Table 2

Supplemental File of Reconstruction MethodsTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

“Incomplete” Patient Sensitivity Analysis

Explanation of "Incomplete" patients (n = 6) and sensitivity analysisTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Plant lipid bodies traffic on actin to plasmodesmata motorized by myosin XIs

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