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Although many studies describe ionic liquids (ILs) as potentially greener solvents, few studies address their relationship with the environment. Recent researches suggest that some ILs have toxicity. 1-Butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) was reported to have the lowest toxicity among ILs. In this work, we studied the toxicity of this IL on wheat seedlings. It was shown that wheat germination was reduced to 38.0% in the presence of 4.4 mmol/L [C4mim][BF4] compared with 100% germination for the control. Similarly, the root and shoot length of wheat seedlings decreased with increasing concentrations of [C4mim][BF4]. The activity of amylase increased in shoots and roots, but it decreased significantly in germinating seeds when the [C4mim][BF4] concentration exceeded 1.8 mmol/L. Peroxidase (POD) activity and soluble protein content in shoots treated with [C4mim][BF4] changed similarly, but chlorophyll content tended to decrease with increasing concentration of [C4mim][BF4], except for at 1.8 mmol/L. Thus, [C4mim][BF4] at the concentration of 0.9 mmol/L or more was toxic to wheat seedlings. Some remedial measures are suggested to deal with IL pollution in the environment.

To evaluate the effects of a worldwide used plant growth regulator mepiquat chloride on the nutrition value and safety of seeds of transgenic Bt cotton, inorganic element components and contents in seeds of Bt cotton (Gossypium hirsutum cv. Guoxin 6) under field condition were determined using ICP-MS. In Bt cotton seeds, 54 kinds of inorganic elements were identified by ICP-MS, and 5 kinds of major elements, K, P, Mg, Ca and Na, were in range from 138.3 to 13,835.1 microg x g(-1). The contents of 14 kinds of microelements were determined as in descending order of Si, B, Mn, Sr, Zn, Ni, Cu, Mo, Fe, Co, Se, V, I and Sn, in the range from 14.2 ng x g(-1) to 81.7 microg x g(-1). Five kinds of heavy metals were detected with the contents from 0.14 to 55.3 ng x g(-1), and their order from high to low is Pb, Cd, Cr, As and Hg. Other 30 kinds of elements were also detected in Bt cotton seeds by ICP-MS, including Rb, Be, La, Ce, Pr, Nd, Sm, Gd, Ge, Rh, Ag, Sb, W, U and Y. Foliar application of mepiquat chloride significantly reduced the contents of Ca, Fe, Si, Mn, Co, Ni, Cu and I, and remarkably decreased heavy metals Pb, Cd and Cr in the cotton seeds, by 68%, 67% and 54% respectively. While mepiquat chloride did not change the contents of most major and micro elements, it heightened 8 kinds, but lowered 7 kinds of the other 30 trace elements. This research indicated that mepiquat chloride application strengthened the security regarding the cotton seed as the material of cooking oil.

The constituents of the roots bleeding sap are an important index characteristic of roots activity and roots-shoots relationship. To compare the differences between the constituents of roots bleeding sap from maize and soybean plants, roots bleeding saps were collected from maize (Zea mays L. cultivar 3138) and soybean [Glycine max (L.) Merr. cultivar Ludou 11] plants at different growth and development stages under field condition, and the inorganic elements were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results indicated that both the constituents of inorganic elements and flow intensities were various between roots bleeding saps from maize and soybean plants at different growth and development stages. The flux of inorganic elements in roots bleeding sap showed different trends with progress in plants growth and development. In the roots bleeding sap from maize, the predominant inorganic elements were K, Ca, Mg, P, Na, Si, Zn, Mn and Fe, with flux ranging from 1 to 1 851.5 microg x h(-1) x plant(-1). The flux of B, Cu and Mo was relatively lower and less than 1 microg x h(-1) x plant(-1), while none of the elements of Co, Cd, Ba, Pb, Sr and As could be detected, and was estimated to be lower than 0.01 microg x h(-1) x plant(-1) based on the detection limit. The flow of most inorganic elements showed decreasing trends with plant development progressing from booting to grain filling stage. In the roots bleeding sap from soybean, Ca, Mg, K, P, Na, Zn, Mn, Fe and Cu were found as predominant inorganic constituents, ranging from 1 to 1 158 microg x h(-1) x plant(-1). The flow of both B and Mo was found lower than 1 microg x h(-1) x plant(-1), and none of Si, Co, Cd, Ba, Pb, Sr and As could be found. With the growth and development, different inorganic elements showed various changing pattern.

MicroRNAs (miRNAs) are a class of small regulatory RNAs, which repress gene expression at the posttranscriptional levels through binding to target mRNAs for directly cleaving mRNAs or inhibiting protein translation. Mature miRNAs are produced from miRNA genes by multiple biological processes, in which several important enzymes are involved in. To date, several hundreds of miRNAs have been identified in plants using a various computational and/or experimental approaches. These miRNAs regulate plant tissue differentiation, development and growth, control auxin signal transduction, involve in plant response to a variety of abiotic and biotic environmental stresses.

Objective: To study the effects of HKL-4 on physiological changes during growth of leaves., Method: Using licorice (Glycyrrhiza uralensis) as material, the effects of HKL-4 on active oxygen metabolism and photochemical efficiency in licorice leaf were determined under field condition., Result and Conclusion: The contents of chlorophyll, activity of SOD and CAT increased, while the MDA contents in leaves decreased. The senescence was delayed, so that the photochemical efficiency (Fv/Fm) was increasing comparing to the control.