Abstract
Crop production is highly sensitive to elevated temperatures. A rise of a few degrees above the optimum growing temperature can lead to a dramatic yield loss. A predicted increase of 1–3 degrees in the twenty first century urges breeders to develop thermo-tolerant crops which are tolerant to high temperatures. Breeding for thermo-tolerance is a challenge due to the low heritability of this trait. A better understanding of heat stress tolerance and the development of reliable methods to phenotype thermo-tolerance are key factors for a successful breeding approach. Plant reproduction is the most temperature-sensitive process in the plant life cycle. More precisely, pollen quality is strongly affected by heat stress conditions. High temperature leads to a decrease of pollen viability which is directly correlated with a loss of fruit production. The reduction in pollen viability is associated with changes in the level and composition of several (groups of) metabolites, which play an important role in pollen development, for example by contributing to pollen nutrition or by providing protection to environmental stresses. This review aims to underline the importance of maintaining metabolite homeostasis during pollen development, in order to produce mature and fertile pollen under high temperature. The review will give an overview of the current state of the art on the role of various pollen metabolites in pollen homeostasis and thermo-tolerance. Their possible use as metabolic markers to assist breeding programs for plant thermo-tolerance will be discussed.
Highlights
Environmental stresses are important factors affecting worldwide crop production [1]
The loculus is surrounded by the tapetum which provides nutrition, metabolites and enzymes required for the development and the protection of the pollen before it degenerates during mitosis
Pollens are very sensitive to heat and can be affected by heat stress during different developmental stages
Summary
Environmental stresses are important factors affecting worldwide crop production [1]. Several experimental parameters can be measured to monitor thermo-tolerance [3], including cell membrane thermostability, photosynthesis activity, pollen viability and fruit set. HSPs are involved in protein homeostasis in order to avoid protein misfolding, protein aggregation or protein degradation They are closely linked with thermo-tolerance and play a crucial role in stress signal transduction [20]. In addition to HSPs, plants can produce different osmolytes and antioxidants to protect themselves from various abiotic stresses, including heat stress [21]; Proline, glycine betaine and aminobutyric acid are key compounds in the osmolyte response under high temperature [22,23,24]. We will discuss various breeding strategies for pollen thermo-tolerance based on the use of metabolic markers
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
