Plasticity of mesophyll cell density and cell wall thickness and composition play a pivotal role in regulating plant growth and photosynthesis under shading in rapeseed.

BACKGROUND AND AIMS: Plasticity of leaf growth and photosynthesis is an important strategy of plants to adapt to shading stress; however, their strategy of leaf development to achieve a simultaneous increase in leaf area and photosynthesis under shading remains unknown. METHODS: In the present study, a pot experiment was conducted using three rapeseed genotypes of Huayouza 50 (HYZ50), Zhongshuang 11 (ZS11) and Huayouza 62 (HYZ62), and the responses of plant growth, leaf morphoanatomical traits, cell wall composition and photosynthesis to shading were investigated. KEY RESULTS: Shading significantly increased leaf area per plant (LAplant) in all genotypes, but the increase in HYZ62 was greater than that in HYZ50 and ZS11. The greater increment of LAplant in HYZ62 was related to the larger decrease in leaf mass per area (LMA) and leaf density (LD), which were in turn related to less densely packed mesophyll cells and thinner cell walls (Tcw). Moreover, shading significantly increased photosynthesis in HYZ62 but significantly decreased it in HYZ50. The enhanced photosynthesis in HYZ62 was related to increased mesophyll conductance (gm) due primarily to thinner cell walls. CONCLUSIONS: The data presented indicate that the different plasticity of mesophyll cell density, cell wall thickness and cell wall composition in response to shading can dramatically affect leaf growth and photosynthesis.

High-Efficiency and Stable Perovskite Solar Cells Prepared Using Chlorobenzene/Acetonitrile Antisolvent.

Preparing high-quality perovskite film with large grain size and fewer trap states is of vital importance in boosting the efficiency and stability of perovskite solar cells (PSCs). However, it is still difficult to obtain perfect MAPbI3 films by antisolvent treatment so far because of the small grain size, pinholes, and numerous defects in perovskite layers. Herein, acetonitrile (ACN) was introduced into chlorobenzene (CB) antisolvent to modify the MAPbI3 active layer. The results show that the ACN could control the ratio of the DMSO in MAI-PbI2-DMSO intermediate phase film effectively and thus manipulate the formation of MAPbI3 film. Relatively high-quality perovskite films with larger grain size were obtained when we added 6% v/v ACN into CB antisolvent. Based on the ACN-modified MAPbI3 film, the n-i-p planar device with the structure of FTO/SnO2/MAPbI3/spiro-OMeTAD/Ag yields the best power conversion efficiency (PCE) of 18.9%. It exhibited an enhancement of 16.6% in efficiency compared with the PCE of 16.2% for the control device. In addition, the device based on ACN-modified MAPbI3 also presents improved stability in air atmosphere.