ABSTRACT
Plant pollen tubes and root hairs typical polarized tip growth. It is well established that calcium ions (Ca2+) play essential roles in maintaining cell polarity and guiding cell growth orientation. Ca2+ signals are encoded by Ca2+ channels and transporters and are decoded by a variety of Ca2+-binding proteins often called Ca2+ sensors, in which calcineurin B-like protein (CBL) proteins function by interacting with and activating a group of kinases, activate CBL-interacting protein kinases (CIPKs). Some CBL-CIPK complexes, such as CBL2/3-CIPK12/19, act as crucial regulators of pollen tube growth. Whether these calcium decoding components regulate the growth of root hairs, another type of plant cell featuring Ca2+-regulated polarized growth, remains unknown. In this study, we identified CIPK13 and CIPK18 as genes specifically expressed in Arabidopsis (Arabidopsis thaliana) root hairs. The cipk13 cipk18 double mutants showed reduced root hair length and lower growth rates. The calcium oscillations at the root hair tip were attenuated in the cipk13 cipk18 mutants as compared to the wild-type plants. Through yeast two-hybrid screens, CBL2 and CBL3 were identified as interacting with CIPK13 and CIPK18. cbl2 cbl3 displayed a shortened root hair phenotype similar to cipk13 cipk18. This genetic analysis, together with biochemical assays showing activation of CIPK13/18 by CBL2/3, supported the conclusion that CBL2/3 and CIPK13/18 may work as Ca2+-decoding modules in controlling root hair growth. Thus, the findings that CIPK12/19 and CIPK13/18 function in pollen tube and root hair growth, respectively, illustrate a molecular mechanism in which the same CBLs recruit distinct CIPKs in regulating polarized tip growth in different types of plant cells.
ABSTRACT
Designing active and stable electrocatalysts with economic efficiency for oxygen evolution reaction (OER) is essential for developing water splitting process at an industrial scale. Herein, we rationally designed a tungsten doped iron cobalt phosphide incorporated with carbon (Wx-FeCoP2/C), prepared by a mechanochemical approach. X-ray photoelectron spectroscopy (XPS) revealed that the doping of W led to an increasing of Co3+/Co2+ and Fe3+/Fe2+ molar ratios, which contributed to the enhanced OER performance. As a result, a current density of 10 mA cm-2 was achieved in 1 M KOH at an overpotential of 264 mV on the optimized W0.1-FeCoP2/C. Moreover, at high current density of 100 mA cm-2, the overpotential value was 310 mV, and the corresponding Tafel slope was measured to be 48.5 mV dec-1, placing it among the best phosphide-based catalysts for OER. This work is expected to enlighten the design strategy of highly efficient phosphide-based OER catalysts.
ABSTRACT
Loquat fruits are among the most popular Chinese fruits because of their unique taste and aroma. The quality profiles of these fruits during 18 days of shelf-life at 20 °C were elucidated by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), E-nose, and E-tongue. During shelf-life period, the properties and variations of 43 (20 aldehydes, 7 esters, 6 ketones, 1 alcohol, and 1 furan) volatile flavored compounds were determined by GC-IMS, which showed that the contents of methyl 3-methyl butanoate, ethyl acetate, and dimethyl ketone gradually decrease with prolonged shelf-life time, while (E)-2-heptenal, heptanal, (E)-2-pentenal, 1-penten-3-one 3-pentanone and 2-pentylfuran increase. The PCA based on the signal intensity of GC-IMS and E-nose, revealed that loquat fruits are well distinguished at different shelf-life times. The taste profile alternates as the storage time increases, along with higher pH, and lower amounts of total soluble solids, vitamin C, and total phenolics. The visual plots of GC-IMS, E-nose, and E-tongue had good consistency, and they characterized the aroma characteristics of loquat fruits well during different shelf-life periods. The findings of this research provide a useful understanding of the flavors of loquat fruits during their prolonged shelf-life, and a potential research basis for advancements in the loquat industry.
ABSTRACT
Plants encounter a variety of mechanical stimuli during their growth and development. It is currently believed that mechanosensitive ion channels play an essential role in the initial perception of mechanical force in plants. Over the past decade, the study of Piezo, a mechanosensitive ion channel in animals, has made significant progress. It has been proved that the perception of mechanical force in various physiological processes of animals is indispensable. However, little is still known about the function of its homologs in plants. In this study, by investigating the function of the AtPiezo gene in the model plant Arabidopsis thaliana, we found that AtPiezo plays a role in the perception of mechanical force in plant root cap and the flow of Ca2+ is involved in this process. These findings allow us to understand the function of AtPiezo from the perspective of plants and provide new insights into the mechanism of plant root cap in response to mechanical stimuli.