ABSTRACT
BACKGROUND: In plants, gravity directs bidirectional growth; it specifies upward growth of shoots and downward growth of roots. Due to gravity, roots establish robust anchorage and shoot, which enables to photosynthesize. It sets optimum posture and develops plant architecture to efficiently use resources like water, nutrients, CO2, and gaseous exchange. Hence, gravitropism is crucial for crop productivity as well as for the growth of plants in challenging climate. Some SGR members are known to affect tiller and shoot angle, organ size, and inflorescence stem in plants. AIM OF REVIEW: Although the SHOOT GRAVITROPISM (SGR) family plays a key role in regulating the fate of shoot gravitropism, little is known about its function compared to other proteins involved in gravity response in plant cells and tissues. Moreover, less information on the SGR family's physiological activities and biochemical responses in shoot gravitropism is available. This review scrutinizes and highlights the recent developments in shoot gravitropism and provides an outlook for future crop development, multi-application scenarios, and translational research to improve agricultural productivity. KEY SCIENTIFIC CONCEPTS OF REVIEW: Plants have evolved multiple gene families specialized in gravitropic responses, of which the SGR family is highly significant. The SGR family regulates the plant's gravity response by regulating specific physiological and biochemical processes such as transcription, cell division, amyloplast sedimentation, endodermis development, and vacuole formation. Here, we analyze the latest discoveries in shoot gravitropism with particular attention to SGR proteins in plant cell biology, cellular physiology, and homeostasis. Plant cells detect gravity signals by sedimentation of amyloplast (starch granules) in the direction of gravity, and the signaling cascade begins. Gravity sensing, signaling, and auxin redistribution (organ curvature) are the three components of plant gravitropism. Eventually, we focus on the role of multiple SGR genes in shoot and present a complete update on the participation of SGR family members in gravity.
ABSTRACT
Malathion is an organophosphate chemical (OPC) and a toxic contaminant that adversely impacts food quality, human health, biodiversity, and the environment. Due to its small size and unavailability of sensitive sensors, detection of malathion remains a challenging task. Often chromatographic methods employed to analyze OPCs suffer from several shortcomings, including cost, immobility, laboriousness, and unsuitability for point-of-care settings. Hence, developing a specific and sensitive diagnostic sensor for quick and inexpensive food testing is essential. We discovered four unique malathion-specific ssDNA aptamers; designed two independent sensing strategies using fluorescence labeling and Thioflavin T (ThT) displacement. Selected aptamers formed the G4-quadruplex-like (G4Q) structure, which helped develop a label-free detection approach with a 2.01 ppb limit of detection. Additionally, 3D structures of aptamers were generated and validated using a series of computational modeling programs. Furthermore, we explored structural features using CD spectroscopy and molecular docking, probing ligands' binding mode, and revealed vital intermolecular interactions with aptamers. Subsequently, the novel sensors were optimized to detect malathion from food samples. The novel sensors could be further developed to meet the demands of sensing and quantifying toxic contaminants from real food samples in field conditions.
ABSTRACT
BACKGROUND: In vitro experiments and limited animal studies suggest that aspirin and nonsteroidal anti-inflammatory drugs may inhibit pancreatic carcinogenesis. Because few studies have examined the association between aspirin use and pancreatic cancer in humans and the results have been inconsistent, we examined the relationship between aspirin use and the development of pancreatic cancer in the Nurses' Health Study. METHODS: Among 88 378 women without cancer at baseline, we documented 161 cases of pancreatic cancer during 18 years of follow-up. Aspirin use was first assessed at baseline in 1980 and updated biennially thereafter. All statistical tests were two-sided. RESULTS: Participants were classified according to history of aspirin use. In a multivariable analysis, the risk of pancreatic cancer was not associated with current regular aspirin use (defined as two or more standard tablets per week; relative risk [RR] = 1.20, 95% confidence interval [CI] = 0.87 to 1.65), compared with use of fewer than two tablets per week. Increasing duration of regular aspirin use, compared with non-use, was associated with a statistically significant increase in risk: Women who reported more than 20 years of regular aspirin use had an increased risk of pancreatic cancer (RR = 1.58, 95% CI = 1.03 to 2.43; P(trend) =.01). Among women who reported aspirin use on at least two of three consecutive biennial questionnaires compared with consistent non-users of aspirin, the risk increased with dose (one to three tablets per week: RR = 1.11, 95% CI = 0.70 to 1.76; four to six tablets per week: RR = 1.29, 95% CI = 0.70 to 2.40; seven to 13 tablets per week: RR = 1.41, 95% CI = 0.76 to 2.61; and > or = 14 tablets per week: RR = 1.86, 95% CI = 1.03 to 3.35) (P(trend) =.02). CONCLUSION: Extended periods of regular aspirin use appear to be associated with a statistically significantly increased risk of pancreatic cancer among women.
