Chilling to zero degrees disrupts pollen formation but not meiotic microtubule arrays in Triticum aestivum L.

Abstract

Throughout the wheat-growing regions of Australia, chilling temperatures below 2 °C occur periodically on consecutive nights during the period of floral development in spring wheat (Triticum aestivum L.). In this study, wheat plants showed significant reductions in fertility when exposed to prolonged chilling temperatures in controlled environment experiments. Among the cultivars tested, the Australian cultivars Kite and Hartog had among the lowest levels of seed set due to chilling and their responses were investigated further. The developmental stage at exposure, the chilling temperature and length of exposure all influenced the level of sterility. The early period of booting, and specifically the +4 cm auricle distance class, was the most sensitive and corresponded to meiosis within the anthers. The response of microtubules to chilling during meiosis in Hartog was monitored, but there was little difference between chilled and control plants. Other abnormalities, such as plasmolysis and cytomixis increased in frequency, were associated with death of developing pollen cells, and could contribute to loss of fertility. The potential for an above-zero chilling sensitivity in Australian spring wheat varieties could have implications for exploring the tolerance of wheat flower development to chilling and freezing conditions in the field.

Effect of n-butanol and cold pretreatment on the cytoskeleton and the ultrastructure of maize microspores when cultured in vitro

“…Early cold-induced disruption of microtubules and subsequent formation of new filaments were observed in cold tolerant wheat genotypes (Abdrakhamanova et al 2003), suggesting the dynamic behavior of microtubules during long-term cold exposure. Besides this, cold stress sensitivity of microtubule network in microspores may show developmental stage dependency according to recent publications (De Storme et al 2012;Barton et al 2014), in which cold treatment only affected microtubular organization during the telophase of meiosis.…”

Behavior of nucleolus in the tobacco male meiocytes involved in cytomixis

“…Analogous localization of the nucleolus in cytomictic nuclei is evident when considering the cytomictic patterns described in different plant species, such as the cacti of the genus Consolea and various cereal species-wheat, rye, and so on (Negron-Ortiz 2007; Barton et al, 2014;Sidorchuk et al, 2016). However, the authors of the mentioned works did not pay attention to the nonrandom nucleolus localization in the migrating nuclei.…”

Why Self-fertilizing Plants Still Exist in Wild Populations: Diversity Assurance through Stress-Induced Male Sterility May Promote Selective Outcrossing and Recombination

“…The concept advanced in this paper, which we call Diversity Assurance, builds on the extensive literature on the effect of heat on pollen development. However, many of the implications that follow hold equally for the male-sterilizing effects of cold, drought and other stresses on seed plants [10,11,15,[20][21][22]. Müller and Rieu proposed a similar idea based on the high temperature response of pollen, but did not expand on it or underpin it with a body of supportive evidence and reasoning [23].…”