Search

Auxin inactivation is critical for plant growth and development. To develop plant growth regulators functioning in auxin inactivation pathway, we performed a phenotype-based chemical screen in Arabidopsis and identified a chemical, nalacin, that partially mimicked the effects of auxin. Genetic, pharmacological, and biochemical approaches demonstrated that nalacin exerts its auxin-like activities by inhibiting indole-3-acetic acid (IAA) conjugation that is mediated by Gretchen Hagen 3 (GH3) acyl acid amido synthetases. The crystal structure of Arabidopsis GH3.6 in complex with D4 (a derivative of nalacin) together with docking simulation analysis revealed the molecular basis of the inhibition of group II GH3 by nalacin. Sequence alignment analysis indicated broad bioactivities of nalacin and D4 as inhibitors of GH3s in vascular plants, which were confirmed, at least, in tomato and rice. In summary, our work identifies nalacin as a potent inhibitor of IAA conjugation mediated by group II GH3 that plays versatile roles in hormone-regulated plant development and has potential applications in both basic research and agriculture.

A factor of 2 difference is found between microwave brightness temperature (TB) observations and simulations from vector radiative transfer models. A physical explanation of this difference is related to the calibration process. In principle, for the calibration of polarimetric instruments of a total power radiometer, the radiation should be only half of the values derived from Planck function but in the actual calibration process, a full value is used. When this full value is converted to a TB it is approximately, but not exactly, twice the TB simulated by a vector radiative transfer model. This inconsistency is verified by simulations of three conically scanning microwave imagers (WindSat, AMSR2 and MWRI) and one cross‐track scanning microwave sounder (AMSU‐A). This difference cannot be compensated simply by dividing a factor of 2 to the processed TBs, especially at high frequencies or at low physical temperatures due to the nonlinear property of Planck function. Plain Language Summary: A factor of 2 difference is found between the radiative transfer simulations and passive microwave brightness temperature observations. This difference results from the two‐point calibration process, which adopts a full Planck function for both vertical and horizontal polarizations instead of using half values. It is a common issue that requires more attentions since the difference cannot be compensated at high frequencies or at low physical temperatures due to the nonlinear relationship between Planck emission and physical temperature. Key Points: A factor of 2 difference is found in the microwave brightness temperature observations compared to vector radiative transfer simulationsThis results from the non‐physical conventions used in the representation of brightness temperature and radiance in calibrationsSpace agencies and the developers of radiative transfer models should recognize and address this issue [ABSTRACT FROM AUTHOR]

SUMMARY: Leaf size is a crucial agronomic trait directly affecting crop yield, which is mainly determined by coordinated cell proliferation, growth, and differentiation. Although endoreduplication is known to be correlated with the onset of cell differentiation and leaf size, the underlying molecular mechanisms are largely unclear. The DnaJ‐like zinc finger domain‐containing protein ORANGE (OR) was initially demonstrated to confer the massive accumulation of carotenoids in cauliflower curds. However, the cauliflower or mutant also possesses other phenotypes such as smaller curds, smaller leaves with elongated petioles, and delayed flowering. Here, we demonstrated that OR physically interacts with the transcription factor TCP7, which promotes endoreduplication by inducing the expression of the cell cycle gene CYCLIN D 1;1 (CYCD1;1). Overexpression of OR resulted in smaller rosette leaves, whereas the OR‐silencing plants had larger rosette leaves than wild‐type plants. Our microscopic observations and flow cytometry analysis revealed that the variation in leaf size was a result of different endoreduplication levels. Genetic analyses showed that OR functions antagonistically with TCP7 in regulating the endoreduplication levels in leaf cells. While the expression of OR is induced by TCP7, OR represses the transactivation activity of TCP7 by affecting its binding capability to the TCP‐binding motif in the promoter region of CYCD1;1. Through this interaction, OR negatively regulates the expression of CYCD1;1 and reduces the nuclear ploidy level in rosette leaf cells. Our findings provide new insights into the regulatory network of leaf size and also reveal a regulatory circuit controlling endoreduplication in leaf cells. Significance Statement: The zinc finger domain‐containing protein ORANGE (OR) has been reported to possess multiple functions in regulating carotenoid biosynthesis, petiole elongation, flowering, and de‐etiolation. Here, we demonstrated that, by repressing the transactivation activity of TCP7 through protein–protein interaction, OR negatively regulates the expression of the cell cycle gene CYCD1;1 and reduces the nuclear ploidy level in rosette leaf cells. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to describe diabetes distress and related factors among Chinese Americans with type 2 diabetes in New York City (NYC). Methods: We conducted a secondary data analysis of the baseline data from three research studies conducted among community-dwelling Chinese American adults with type 2 diabetes. Diabetes Distress Scale (DDS) was used to measure sources of diabetes distress including emotional-, regimen-, interpersonal-, and physician-related distress. A score of 2 or greater indicates moderate diabetes distress or higher. Patient Health Questionnaire-2 (PHQ-2) was used to measure depressive symptoms. Participants' sociodemographic information was also collected. Descriptive statistics were used to describe diabetes distress, and logistic least absolute shrinkage and selection operator (LASSO) regression was used to examine factors associated with diabetes distress level. Results: Data from 178 participants (mean age 63.55± 13.56 years) were analyzed. Most participants were married (76.40%), had a high school degree or less (65.73%), had a household annual income < $25,000 (70.25%), and reported limited English proficiency (93.22%). About 25.84% reported moderate or higher overall distress. The most common sources of distress were emotional burden (29.78%), followed by regimen- (28.65%), interpersonal- (18.54%), and physician-related distress (14.04%). Participants who were younger, female, limited English proficient, and had elevated depressive symptoms were more likely to have higher diabetes distress. Conclusion: Diabetes distress is prevalent among Chinese immigrants with type 2 diabetes, especially emotional- and regimen-related distress. Given the known link between diabetes distress and poor glycemic control, it is critical to screen for diabetes distress at primary care clinics and incorporate psychological counseling in diabetes care in this underserved population. [ABSTRACT FROM AUTHOR]