Simultaneous responses of photosystem II and soluble proteins of rapeseed to cold acclimation

Abstract

This experiment was conducted to assess the quantitative and qualitative changes in soluble proteins as well as some chlorophyll fluorescence parameters in the leaves of a winter canola (Brassica napus L., cv. Licord) under continuous low temperature. Over the experiment, seedlings were initially grown at 15/10 °C (d/n). At fourth fully expanded leafy stage (day 30), a part of the plants were transferred to 4/2°C for 4 weeks. Plants were sampled for protein extraction from leaves in which chlorophyll fluorescence parameters (F o , F v , F m , F v/ F o, F m/ F o, F v /F m , F o´, F V´, F m´ and some other calculated) were also measured. The results showed a clear increase in soluble proteins quantity caused by cold treatment. The enhancements appeared abruptly following the cold exposure to 4°C and lasted. The electrophoretic protein patterns showed changes in the intensity of some polypeptides, besides, induction a new probable protein weighing 47-kW in response to cold treatment. Cold-triggered reduction in maximum quantum yield of PSII (F v /F m) was connected especially with drastic decreasing F v and F m. Interestingly, high quantitative amounts of soluble proteins along with induction of the new probable polypeptide induced at cold temperature, were attributed to low deduction of maximum quantum yield of PSII. Additionally, more imperative chlorophyll fluorescence parameters changed e.g. qP, NPQ, qL, Y(II) or ф PSII etc at light. Nowadays, radar charts or spider plots are the most sophisticated multivariate statistical tools representing physiological responses of plants to abiotic stress conditions or even morphophysiological studies of plants. In rapeseed many researches performed by applying the radar charts for low temperature stresses and interpreted their effects more advancely than common statistical tools. We observed a good representation of the chl fluorescence parameters fluctuations using radar plots. Overall, cold-induced soluble proteins accumulated after longer cold-acclimation, can contribute in photosynthetic apparatus protection against low-temperature damages.

Identification and Characterization of a Plant Endophytic Fungus Paraphaosphaeria sp. JRF11 and Its Growth-Promoting Effects

“…Soluble protein was an important osmoregulatory substance and nutrient in plants. Most soluble proteins were enzymes involved in various metabolisms, which can regulate the growth of plants and protect plants against stress [36]. Results showed that the content of soluble protein in JRF11-20-treated plants was significantly increased compared with the control (Figure 5D).…”

CfCHLM, from Cryptomeria fortunei, Promotes Chlorophyll Synthesis and Improves Tolerance to Abiotic Stresses in Transgenic Arabidopsis thaliana

“…In our study, the F v /F m , Y(II), and qP values of A. thaliana showed a decreasing trend under the stress treatments compared to CK (Figures 4K-M, 5K-M and 6K-M). Arminian et al [38] found that the chl fluorescence parameters of canola (Brassica napus L.) leaves decreased during cold. Li et al [39] found that the F v /F m and qP of two different varieties of cucumber (Jinchun No.4, Zhongnong No.12) under high temperatures both decreased.…”

A Chromosome Level Genome Assembly of a Winter Turnip Rape (Brassica rapa L.) to Explore the Genetic Basis of Cold Tolerance

“…Oxidative damage was estimated by measuring the content of MDA as described previously (Du et al, 2010). The content of soluble protein (SP) was measured as previously described (Arminian and Dehghani Bidgoli, 2019). The activity of ROS scavenging enzymes, such as ascorbate peroxidase (APX) activity, peroxidase (POD) activity (Quiroga et al, 2000), superoxide dismutase (SOD) activity, catalase (CAT) activity, were measured as described in previous studies (Quiroga et al, 2000;Yao et al, 2011;Zhang et al, 2013).…”