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Plants as sessile organisms use calcium ions (Ca2+) as secondary messengers to respond to biotic and abiotic stimuli. In order to interpret Ca2+ signatures, plants process many Ca2+ sensor proteins, including the large family of Calmodulin-like proteins (CMLs). The functions of most CMLs in plants remains unclear. CML13 is a biochemically-unique CML whose role in cells is unstudied but recent data from the Snedden Lab suggests it interacts with several cytoskeletal proteins and a class of transcriptional activators. To gain insight into CML13 function, I investigated the gene promoter activity of CML13 in transgenic Arabidopsis at different developmental stages and tissues using CML13-promoter--glucuronidase (GUS) reporter assays. I also explored the phenotype of a cml13 loss-of-function transgenic line. In seeds of cml13 plants, the germination rate was lower than wild-type (WT) plants in response to 1 µM ABA at 24 h and 48 h suggesting CML13 may function in ABA pathways regulating germination. Other than this sensitivity to ABA, cml13 plants did not show any observable phenotypic differences from WT throughout development under my growth conditions. In GUS assays of CML13pro::GUS plants, CML13 promoter activity was detected throughout Arabidopsis development in a variety of tissues. The broad distribution of CML13 may indicate involvement of CML13 in a fundamental or “housekeeping” cell process. The spatial promoter activity at points of lateral-root emergence, and points of probable vascular connection of lateral and parental roots, suggests CML13 may also function in developmental pathways under auxin control but this remains speculative. Collectively, my research suggests a broad expression pattern of CML13 in Arabidopsis and suggests future work should explore a role for CML13 in germination and root patterning.

Atmospheric aerosol particle plays a vital role in the Earth’s radiation budget, affecting human health by raising air pollution events, which have become remarkably common in megacities of China. Three sites in Chengdu city were selected for measurement of air quality index(AQI) and pollutants like PM2.5, PM10, SO2, NO2, whose concentrations were indicators of air quality. The association between air pollution in terms of AQI (pollutants’ concentrations) and meteorological conditions like Relative Humidity(RH) and Wind Velocity(WV) have been evaluated in this study. The results show that AQI peaked on June 22nd and Jul 16th, when PM2.5 and PM10 dominated. Further analysis reveals that only PM2.5 and PM10 are related to RH. In particular, PM2.5(PM10) intends to decrease when RH increases with a coefficient of -0.4(-0.57). However, there is no evident co-variation between RH and SO2(NO2). The results also indicate that concentration of NO2 decreases when WV increases with a coefficient of -0.66. By contrast, corresponding relationship between PM2.5(PM10) and WV is less evident.