Rekha Kushwaha

Unidirectional Movement of Cellulose Synthase Complexes in Arabidopsis Seed Coat Epidermal Cells Deposit Cellulose Involved in Mucilage Extrusion, Adherence, and Ray Formation

Two cellulose synthases interact to synthesize Arabidopsis seed coat mucilage cellulose in a unidirectional manner and promote mucilage adherence and expansion. CELLULOSE SYNTHASE5 (CESA5) synthesizes cellulose necessary for seed mucilage adherence to seed coat epidermal cells of Arabidopsis (Arabidopsis thaliana). The involvement of additional CESA proteins in this process and details concerning the manner in which cellulose is deposited in the mucilage pocket are unknown. Here, we show that both CESA3 and CESA10 are highly expressed in this cell type at the time of mucilage synthesis and localize to the plasma membrane adjacent to the mucilage pocket. The isoxaben resistant1-1 and isoxaben resistant1-2 mutants affecting CESA3 show defects consistent with altered mucilage cellulose biosynthesis. CESA3 can interact with CESA5 in vitro, and green fluorescent protein-tagged CESA5, CESA3, and CESA10 proteins move in a linear, unidirectional fashion around the cytoplasmic column of the cell, parallel with the surface of the seed, in a pattern similar to that of cortical microtubules. Consistent with this movement, cytological evidence suggests that the mucilage is coiled around the columella and unwinds during mucilage extrusion to form a linear ray. Mutations in CESA5 and CESA3 affect the speed of mucilage extrusion and mucilage adherence. These findings imply that cellulose fibrils are synthesized in an ordered helical array around the columella, providing a distinct structure to the mucilage that is important for both mucilage extrusion and adherence.

Sorghum mutant RG displays antithetic leaf shoot lignin accumulation resulting in improved stem saccharification properties

BackgroundImproving saccharification efficiency in bioenergy crop species remains an important challenge. Here, we report the characterization of a Sorghum (Sorghum bicolor L.) mutant, named REDforGREEN (RG), as a bioenergy feedstock.ResultsIt was found that RG displayed increased accumulation of lignin in leaves and depletion in the stems, antithetic to the trend observed in wild type. Consistent with these measurements, the RG leaf tissue displayed reduced saccharification efficiency whereas the stem saccharification efficiency increased relative to wild type. Reduced lignin was linked to improved saccharification in RG stems, but a chemical shift to greater S:G ratios in RG stem lignin was also observed. Similarities in cellulose content and structure by XRD-analysis support the correlation between increased saccharification properties and reduced lignin instead of changes in the cellulose composition and/or structure.ConclusionAntithetic lignin accumulation was observed in the RG mutant leaf-and stem-tissue, which resulted in greater saccharification efficiency in the RG stem and differential thermochemical product yield in high lignin leaves. Thus, the red leaf coloration of the RG mutant represents a potential marker for improved conversion of stem cellulose to fermentable sugars in the C4 grass Sorghum.

Mutagenesis Breeding for Increased 3-Deoxyanthocyanidin Accumulation in Leaves of Sorghum bicolor (L.) Moench: A Source of Natural Food Pigment

Natural food colorants with functional properties are of increasing interest. Prior papers indicate the chemical suitability of sorghum leaf 3-deoxyanthocyanidins as natural food colorants. Via mutagenesis-assisted breeding, a sorghum variety that greatly overaccumulates 3-deoxyanthocyanidins of leaf tissue, named REDforGREEN (RG), has been isolated and characterized. Interestingly, RG not only caused increased 3-deoxyanthocyanidins but also caused increased tannins, chlorogenic acid, and total phenolics in the leaf tissue. Chemical composition of pigments was established through high-performance liquid chromatography (HPLC) that identified luteolinidin (LUT) and apigeninidin (APG) as the main 3-deoxyanthocianidin species. Specifically, 3-deoxyanthocianidin levels were 1768 μg g⁻¹ LUT and 421 μg g⁻¹ APG in RG leaves compared with trace amounts in wild type, representing 1000-fold greater levels in the mutant leaves. Thus, RG represents a useful sorghum mutagenesis variant to develop as a functionalized food colorant.

Identification of Late Embryogenesis Abundant (LEA) Protein Putative Interactors Using Phage Display

Arabidopsis thaliana seeds without functional SEED MATURATION PROTEIN1 (SMP1), a boiling soluble protein predicted to be of intrinsic disorder, presumed to be a LATE EMBRYOGENESIS ABUNDANT (LEA) family protein based on sequence homology, do not enter secondary dormancy after 3 days at 40 °C. We hypothesized that SMP1 may protect a heat labile protein involved in the promotion of secondary dormancy. Recombinant SMP1 and GmPM28, its soybean (Glycine max), LEA4 homologue, protected the labile GLUCOSE-6-PHOSPHATE DEHYROGENASE enzyme from heat stress, as did a known protectant, Bovine Serum Albumin, whether the LEA protein was in solution or attached to the bottom of microtiter plates. Maintenance of a biological function for both recombinant LEA proteins when immobilized encouraged a biopanning approach to screen for potential protein interactors. Phage display with two Arabidopsis seed, T7 phage, cDNA libraries, normalized for transcripts present in the mature, dehydrated, 12-, 24-, or 36-h imbibed seeds, were used in biopans against recombinant SMP1 and GmPM28. Phage titer increased considerably over four rounds of biopanning for both LEA proteins, but not for BSA, at both 25 and at 41 °C, regardless of the library used. The prevalence of multiple, independent clones encoding portions of specific proteins repeatedly retrieved from different libraries, temperatures and baits, provides evidence suggesting these LEA proteins are discriminating which proteins they protect, a novel finding. The identification of putative LEA-interacting proteins provides targets for reverse genetic approaches to further dissect the induction of secondary dormancy in seeds in response to heat stress.

Factors affecting podophyllotoxin yield in the ex situ grown Podophyllum hexandrum, an endangered alpine native of the western Himalayas

This study reports an appreciable yield of podophyllotoxin (PDT) in P. hexandrum plants grown ex situ under polyhouse conditions of a temperate locale. The PDT content of below-ground parts was affected by both plant age and growth period. However, only the effect of plant age on PDT content was significant. Thus, the highest amounts of PDT were recorded in the below-ground parts of 2-year-old plants harvested during the late-growth period (LGP). High total soluble sugars in the below-ground parts during the early growth period (EGP) and the highest nitrate and nitrate reductase in the leaves of 2-year-old plants during the peak-growth period (PGP) indicated higher mobilization and assimilation of starch and nitrate. Probably the surplus carbon and nitrogen gained during the PGP were diverted from aerial parts to below-ground parts during the LGP and in turn contributed to the synthesis of higher amounts of PDT. This study shows that commercial cultivation of P. hexandrum is possible under ex situ temperate conditions.

GA3 induced changes in slow growing endangered Himalayan plant Podophyllum hexandrum and hastening of vegetative growth

The endangered Himalayan plant Podophyllum hexandrum syn. P. emodi is inherently slow growing. The plants exhibit delayed emergence of functional leaves or hypocotyl dormancy. However, on GA3 treatment the functional leaves were found to emerge at a favorable temperature of 25°C in a higher percentage of seedlings and in a shorter time. Functional leaves emerged even at 10°C, a temperature when hypocotyl dormancy generally prevails. A considerable increase in the biochemical parameters related to carbon and nitrogen metabolism [starch, sugars and soluble nitrates, α-amylase and nitrate reductase (NR) activity], respiration and total dehydrogenase activity in all the seedling parts also indicated an enhancement of metabolic processes as influenced by GA3, for further growth and development. Specific leaf area of the green cotyledonary leaves increased at 25°C, probably to meet the carbon and nitrogen requirements for new structure formation. Higher activity of enzymes involved in carbon and nitrogen metabolism, i.e., NR and α-amylase especially at Hbn, the region of leaf meristematic activity, was further indicative of higher metabolism for earlier initiation of rapid vegetative growth. Initiation of reserve accumulation was also observed at 25°C.

Uses of Phage Display in Agriculture: A Review of Food-Related Protein-Protein Interactions Discovered by Biopanning over Diverse Baits

This review highlights discoveries made using phage display that impact the use of agricultural products. The contribution phage display made to our fundamental understanding of how various protective molecules serve to safeguard plants and seeds from herbivores and microbes is discussed. The utility of phage display for directed evolution of enzymes with enhanced capacities to degrade the complex polymers of the cell wall into molecules useful for biofuel production is surveyed. Food allergies are often directed against components of seeds; this review emphasizes how phage display has been employed to determine the seed component(s) contributing most to the allergenic reaction and how it has played a central role in novel approaches to mitigate patient response. Finally, an overview of the use of phage display in identifying the mature seed proteome protection and repair mechanisms is provided. The identification of specific classes of proteins preferentially bound by such protection and repair proteins leads to hypotheses concerning the importance of safeguarding the translational apparatus from damage during seed quiescence and environmental perturbations during germination. These examples, it is hoped, will spur the use of phage display in future plant science examining protein-ligand interactions.

Uses of Phage Display in Agriculture: Sequence Analysis and Comparative Modeling of Late Embryogenesis Abundant Client Proteins Suggest Protein-Nucleic Acid Binding Functionality

A group of intrinsically disordered, hydrophilic proteins—Late Embryogenesis Abundant (LEA) proteins—has been linked to survival in plants and animals in periods of stress, putatively through safeguarding enzymatic function and prevention of aggregation in times of dehydration/heat. Yet despite decades of effort, the molecular-level mechanisms defining this protective function remain unknown. A recent effort to understand LEA functionality began with the unique application of phage display, wherein phage display and biopanning over recombinant Seed Maturation Protein homologs from Arabidopsis thaliana and Glycine max were used to retrieve client proteins at two different temperatures, with one intended to represent heat stress. From this previous study, we identified 21 client proteins for which clones were recovered, sometimes repeatedly. Here, we use sequence analysis and homology modeling of the client proteins to ascertain common sequence and structural properties that may contribute to binding affinity with the protective LEA protein. Our methods uncover what appears to be a predilection for protein-nucleic acid interactions among LEA client proteins, which is suggestive of subcellular residence. The results from this initial computational study will guide future efforts to uncover the protein protective mechanisms during heat stress, potentially leading to phage-display-directed evolution of synthetic LEA molecules.

Association of Serum CRP level with Lung Cancer and Healthy Control of North Indian Population

BackgroundLung cancer is the major cause of cancer-related mortality worldwide. Chronic inflammation of the airway plays an important role in the alternations of bronchial epithelium and lung microenvironment, therefore provoking the pulmonary carcinogenesis and progression of lung cancer. The results may suggest that high inflammation level can be associated with the higher risk of lung cancer. CRP is an acute-phase protein produced in the liver in response to elevated cytokine levels after an inflammatory stimulus. C-reactive protein (CRP) a systemic marker of chronic inflammation is associated with increased lung cancer risk. Material and MethodologyThis case-control study was conducted on 40 lung cancer patients and 30 healthy controls. CRP level was measured in serum by ELISA kits. ResultsElevated serum CRP level was found in lung cancer patients as comparison to healthy controls. This study shows significant association between the serum CRP level of lung cancer patients and healthy controls (p<0.0001) and also showed significant association between smoker, ex-smoker and non-smokers lung cancer patients as well as in healthy controls (p<0.0001). ConclusionHigher CRP levels were found in lung cancer patients as compared to healthy controls. The higher CRP level was also observed in Smoker, Ex-smoker as compared to non-smoker in lung cancer patients and healthy control. Key-wordsLung Cancer, CRP, Inflammatory Stimulus, Cardiovascular disease, Biomarker INTRODUCTION Lung cancer is the major cause of cancer-related mortality in both men and women worldwide [1] . Chronic inflammation in airway plays an important role in the alternations of bronchial epithelium and lung microenvironment provoking the pulmonary carcinogenesis and progression of lung cancer. The results may suggest that high inflammation level can be associated with the higher risk of lung cancer. It is known that pro-inflammatory cytokines such as interleukin 1, interleukin 2, tumor necrosis factor alpha and tumor growth factor are able to stimulate the production of C-reactive protein (CRP) as well as influence survival, growth, mutation, proliferation, differentiation, and migration of tumor cells [2] . C-reactive protein (CRP) a Access this article online Quick Response Code Website:

Study on Association of BMI with Lung Cancer in North Indian Population

BackgroundLung cancer is one of the most prevalent types of cancer in India. It is considered as the most commonly diagnosed cancer and constitutes the leading cause of cancer-related mortality. The majority of lung cancer is due to smoking. Tobacco use has been reported to be one of the main causes of lung cancer. It has been observed in previous studies that excess body weight and obesity are protective factors against lung cancer in current and former smokers. MethodsThe present study recruited 235 lung cancer patients. BMI was categorized as underweight (BMI <18.5 kg/m), normal weight (BMI 18.5 to <25kg/m), overweight (BMI 25 to <30 kg/m) and obese (BMI≥30 kg/m). The study was conducted to establish the association of BMI with gender, smoking status, and histological subtypes of lung cancer. ResultsOut of 235 patients enrolled, 55.32% were underweight, 40.43% were normal weight, 3.4% of patients were classified as overweight and 0.85% was obese. This study showed a significant association of BMI with smoking status (p<0.0057), while the non-significant association with gender (p=0.75) and histological subtypes (p=0.74). ConclusionWe were concluded that significant association was found between BMI and smoking status, while non significant association was observed between BMI and gender as well as BMI and histological subtypes of lung cancer patients in the north Indian population in this study. Key-wordsBMI, Histological Subtypes, Lung Cancer, Mortality, Smoking INTRODUCTION Lung cancer is one of the most prevalent types of cancer in India and constitutes the leading cause of cancer related mortality worldwide . Lung cancer is defined as the uncontrolled cell growth of lung tissues which may lead to metastasis, invasion of adjacent tissue and infiltration beyond the lungs . The majority of lung cancer cases are due to Tobacco smoking and other environmental pollutants have been recognized as risk factors for cancer. The average five-year survival rate after diagnosis is low . It is essential to emphasize the importance of Lung Cancer prevention, and knowledge of modifiable risk factors such as environmental exposures, tobacco smoking and air pollution is prevalent among good quality epidemiological studies that explain the majority of Lung Cancer incidence . The complex interplay of etiological and psychophysical factors is believed to modify the effect of respiratory carcinogens on lung cancer initiation and prognosis . Access this article online Quick Response Code Website: