Function and stress tolerance of seed mitochondria

Abstract

Seeds of higher plant are desiccation tolerant, which suggests that their mitochondria exhibit particular properties. Insight into the function of seed mitochondria, especially in legume and model plants, has been fostered by the development of proteomics. Seed mitochondria are functional at the onset of imbibition, and their integrity and performance systematically improves during germination. This suggests that repair and biogenesis mechanisms exist, and this is supported by morphological and biochemical evidence. Seed mitochondria generate and operate in a hypoxic environment. They accumulate stress proteins, such as a small heat‐shock protein and a late embryogenesis abundant protein. The mitochondria of pea (Pisum sativum L.) seed also display a biased phospholipid composition likely to favour desiccation tolerance. These specific biochemical properties surely contribute to the remarkable tolerance of seed mitochondria to extreme temperatures. Recent progress towards the resolution of the seed mitochondrial proteome is discussed in light of the growing body of genomic data.

Mitochondrial structural and antioxidant system responses to aging in oat (Avena sativa L.) seeds with different moisture contents

“…Although mitochondria in dry seeds are poorly differentiated, they are functional at the onset of imbibition, and their integrity and performance systematically improve during imbibition and germination (Macherel et al, 2007). As a principal organelle in embryo cells, the integrative membrane ultrastructure and normal function of mitochondria are necessary for seeds to maintain high vigor.…”

“…However, the reduction in the antioxidant system of mitochondria results in enhanced H 2 O 2 production and membrane damage (Gupta, 2011). Although advances have been made in understanding mitochondrial H 2 O 2 processing, the mechanisms of mitochondrial H 2 O 2 elimination remain poorly understood (Bewley et al, 2013;Macherel et al, 2007). This may be due to a lack of studies focusing on the relationship between mitochondrial antioxidant systems and their ultrastructures in aged seeds during imbibition.…”

Physiological quality and expression of genes in seeds of Handroanthus serratifolius subjected to drying

“…This role has been attributed to the heat-resistant proteins such as heat shocks, deidrines and LEA proteins. This protection capability is possible due to their highly hydrophilic characteristic that seems to be linked to their occurrence in specifi c cellular structures (Macherel et al, 2007).…”

Alvaradoa amorphoides germination at low water potential and the role of the antioxidant system

“…The treated seeds imbibed as much as the control seeds up to 2 h, then stabilized, and most importantly, did not display the second water uptake increase that the control seeds showed at 48 h. However, the seeds treated at the -0.5 MPa water potential were able to reach 00% of the control seed germination rate after 96 h. The respiratory rate was also monitored during germination due to the importance of this process in maintaining energy metabolism in the seeds and as a major source of ROS (Møller, 200;Bailly, 2004;Macherel et al, 2007;Noctor et al, 2007). In the control seeds, the respiratory rate encompassed three phases (Patanè et al, 2006).…”