Development of a new heat tolerance assay system for rice spikelet sterility

Abstract

Background Reduction in rice yield caused by high temperature-induced spikelet sterility has been a serious concern in rice production. To date, several screening methods have been used, although their reproducibility is sometimes poor due to artifacts mainly caused by varietal differences in heading dates and panicle heights (i.e., the distance from the lamps).MethodsWe have developed a novel assay system for heat-induced spikelet sterility by using artificial rice paddies in phytotrons to conduct a highly reproducible assay throughout a year. Plants restricted to the main culm were treated under a series of heat conditions, and height uniformity of each plant was ensured by using height-adjustable pots.ResultsResults suggested that a 3-day heat treatment of 35 °C-day/29 °C-night cycles was the most suitable condition. Under the treatment, two distinct groups were identified among nine heat tolerant cultivars, with no varietal difference in panicle temperature, indicating that the system is capable of eliminating the varietal difference in panicle temperature.ConclusionsIt is concluded that the assay system would be a powerful tool for selecting heat tolerant varieties, as well as the analysis of genetic factors from various cultivars, eliminating potential artifacts.Electronic supplementary materialThe online version of this article (doi:10.1186/s13007-017-0185-3) contains supplementary material, which is available to authorized users.

A Heat Stress Responsive NAC Transcription Factor Heterodimer Plays Key Roles in Rice Grain Filling

“…4D, E). Previous studies have shown that the ambient temperature higher than 35°C would have a serious impact on the yield at flowering and grain filling stages (Hakata et al, 2017). Therefore, we set 35°C as the heat damage temperature of rice (T B ), and calculated the heat damage accumulated temperature per hour (TH i ), heat damage accumulated temperature during filling stage (T S ) and heat damage hours during filling stage (H S ) as described by Chen (Chen et al, 2019).…”

Multiple strategies for heat adaptation in rice endosperms revealed by on-site cell-specific analysis

“…N supply decreases heat-induced chalky formation (Perez et al, 1996; Wakamatsu et al, 2008), although the underlying mechanisms of heat-induced chalky formation and the N-enhanced adaptation have never been systematically examined mostly due to the technical difficulties at the cellular level. As pointed previously (Hakata et al, 2017), another difficulty for studying heat-related damages in crop plants would be due to the low reproducibility of high-temperature treatment under field conditions, which implies the need of environmental controls. We have developed a new on-site cell metabolomics performable in the controlled environments to make such a cellular analysis possible (Supplementary file 1).…”

Reproductive tissues-specific meta-QTLs and candidate genes for development of heat-tolerant rice cultivars

“…During recent years, significant progress has been made in screening of heat-tolerant rice germplasm at the reproductive stage and elucidating complex molecular-genetic mechanisms underlying heat-tolerance. For example, Hakata et al (2017) developed a new assay system for selection of heat-tolerant rice genotypes with no varietal difference in panicle temperature. Lafarge et al (2017) conducted a genome-wide association analysis on a large set of indica rice germplasm during anthesis and identified several heat stress linked single nucleotide polymorphisms (SNPs) associated with spikelet sterility.…”