Effect of chilling on photosynthesis and antioxidant enzymes in Hevea brasiliensis Muell. Arg.

Abstract

The aim of the present study was to assess the tolerance of Hevea brasiliensis to chilling temperatures since rubber production has been extended to sub-optimal environments. PB260 clone was used to analyze the responses of leaves chilled at 10°C during 96 h, as well as their recovery at 28°C. Some key parameters were used to evaluate photosynthetic apparatus functioning, membrane damage (electrolyte leakage) and oxidative stress. A shortterm response versus a long-term one have been recorded, the time point of 24 h, when stomata closure was effective, being the border between the two responses. P n decreased dramatically at 1 h, and Fv/Fm was slightly affected. NPQ reached its maximal level between 4 and 7 h. Lipid peroxidation and membrane lysis were observed between 48 and 96 h. Activities of antioxidant enzymes increased, along with the induction of antioxidant gene expression. Finally, the plants were capable to recover (net photosynthetic rate, photochemical efficiency, antioxidant enzymes activities) when placed back to 28°C showing that PB260 can withstand long-term chilling.

Effect of diurnal irradiance on night-chilling tolerance of six rubber cultivars

“…P max was significantly decreased by night chilling treatment at 10°C, which was returned to 45-85% of pretreatment levels after a 3-day recovery (Table 1S). Our results were consistent with a previously reported study by Mai et al (2009), in which rubber trees were showed to withstand 4 days of chilling at 10°C and 50% of its photosynthetic ability was recovered after 3 days at 28°C. We suggest that night chilling at 10°C for several days does not cause any irreversible damage in the photosynthetic system of rubber trees; however, night chilling at 0-5°C in combination with subsequent full irradiance can cause evident photodamage in rubber trees.…”

“…More than half of the soluble proteins are important components of the photosynthetic apparatus and photodamage repair process (Pell et al 1994, Asada 2006, Danon 2012, and soluble proteins also play an important role in osmotic adjustment (He et al 2013). MDA, which is the product of membrane lipid peroxidation, was significantly increased after night chilling treatments at 5°C and 0°C, indicating that night chilling might induce the accumulation of ROS, and impair cell membranes of the photosynthetic system (Thomashow 1999, Mai et al 2009, Lei et al 2014. MDA and ROS can suppress the activities of photosynthetic enzymes such as ribulose-1,5-bisphosphate carboxylase/oxygenase.…”

No trade-off between hydraulic and mechanical properties in several transgenic poplars modified for lignins metabolism

“…RNA was isolated using CTAB extraction buffer as described by Chang et al (1993) and stored at −80 • C. First strand cDNAs were synthesized by reverse transcription using 2 g of total RNA in a final reaction volume of 20 l using the Super Script TM III first strand synthesis system for RT-PCR (Invitrogen, Paisley, UK) according to the manufacturer's instructions. PCR amplifications were performed as described by Mai et al (2009) using the primers indicated in Table 1. The PCR products were ligated into PGEM-Teasy vector (Promega, Charbonnières, France) and transformed into DH5␣ Escherichia coli strain, and the sequences were checked.…”

Putative role of proteins involved in detoxification of reactive oxygen species in the early response to gravitropic stimulation of poplar stems

“…The real-time RT-PCR amplifications were done according to Mai et al 34 with the specific primers reported in Table 1. The oligonucleotides primers were constructed based on specific Populus EST database [http://genome.jgi-psf.org] the EST detected with the BLAST program.…”