Salicylic acid reverses pollen abortion of rice caused by heat stress.

ABSTRACT:

Background

Extremely high temperatures are becoming an increasingly severe threat to crop yields. It is well documented that salicylic acid (SA) can enhance the stress tolerance of plants; however, its effect on the reproductive organs of rice plants has not been described before. To investigate the mechanism underlying the SA-mediated alleviation of the heat stress damage to rice pollen viability, a susceptible cultivar (Changyou1) was treated with SA at the pollen mother cell (PMC) meiosis stage and then subjected to heat stress of 40 °C for 10 d until 1d before flowering.

Results

Under control conditions, no significant difference was found in pollen viability and seed-setting rate in SA treatments. However, under heat stress conditions, SA decreased the accumulation of reactive oxygen species (ROS) in anthers to prevent tapetum programmed cell death (PCD) and degradation. The genes related to tapetum development, such as EAT1 (Eternal Tapetum 1), MIL2 (Microsporeless 2), and DTM1 (Defective Tapetum and Meiocytese 1), were found to be involved in this process. When rice plants were exogenously sprayed with SA or paclobutrazol (PAC, a SA inhibitor)?+?H₂O₂ under heat stress, a significantly higher pollen viability was found compared to plants sprayed with H₂O, PAC, or SA?+?dimethylthiourea (DMTU, an H₂O₂ and OH· scavenger). Additionally, a sharp increase in H₂O₂ was observed in the SA or PAC+ H₂O₂ treatment groups compared to other treatments.

Conclusion

We suggest that H₂O₂ may play an important role in mediating SA to prevent pollen abortion caused by heat stress through inhibiting the tapetum PCD.

SUBMITTER: Feng B 

PROVIDER: S-EPMC6194599 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature