Seed set, pollen morphology and pollen surface composition response to heat stress in field pea

Abstract

Pea (Pisum sativum L.) is a major legume crop grown in a semi-arid climate in Western Canada, where heat stress affects pollination, seed set and yield. Seed set and pod growth characteristics, along with in vitro percentage pollen germination, pollen tube growth and pollen surface composition, were measured in two pea cultivars (CDC Golden and CDC Sage) subjected to five maximum temperature regimes ranging from 24 to 36 °C. Heat stress reduced percentage pollen germination, pollen tube length, pod length, seed number per pod, and the seed-ovule ratio. Percentage pollen germination of CDC Sage was greater than CDC Golden at 36 °C. No visible morphological differences in pollen grains or the pollen surface were observed between the heat and control-treated pea. However, pollen wall (intine) thickness increased due to heat stress. Mid-infrared attenuated total reflectance (MIR-ATR) spectra revealed that the chemical composition (lipid, proteins and carbohydrates) of each cultivar's pollen grains responded differently to heat stress. The lipid region of the pollen coat and exine of CDC Sage was more stable compared with CDC Golden at 36 °C. Secondary derivatives of ATR spectra indicated the presence of two lipid types, with different amounts present in pollen grains from each cultivar.

Identification of High-Temperature Tolerant Lentil (Lens culinaris Medik.) Genotypes through Leaf and Pollen Traits

“…“At the time of reproduction, a brief phase of high temperature may decrease the number of floral buds and augment abortion of flowers abortion, significantly, though variations occur in the response within and amid plant species as well as their genotypes” (Annisa et al, 2013; Kaushal et al, 2013; Sage et al, 2015). Investigations involving exposure to moderate heat stress at various reproductive stages have associated development and performance of pollen grains as being highly susceptible to elevated temperature stress (Kaushal et al, 2013; Jiang et al, 2015; Sage et al, 2015). High temperatures may interrupt reproductive function by changing the concentrations of phytohormones like auxins (Teale et al, 2006) and abscisic acid (Todaka et al, 2012).…”

Pollen viability of Tepary bean (Phaseolus acutifolius A. Gray.) mutant lines under water stress conditions and inoculation with rhizobia

“…the average viability percentage with irrigation was of 98.37 %, while the one with drought was of 96.85 %. However, it is possible that morphological pollen staining could have overestimated the percentage of pollen viability as has already been reported in other works (González, Estévez, Castillo, Salomón, Moré & Hernandez, 2002); in this sense, readings of such a high viability in all treatments could have been biased, and there were normally variations, as has been reported in other legumes, where pollen germination percentage was reduced by heat stress (Jiang, Lahlali, Karunakaran, Kumar, Davis & Bueckert, 2015). However, it should be noted that this technique was used because it allowed the preservation of the original pollen grain structure (from the time they were collected) in the fixative solution, before these were processed for analysis; therefore, we also thought of estimating an additional pollen production indicator.…”

Analysis of morphological and molecular composition changes in allergenic Artemisia vulgaris L. pollen under traffic pollution using SEM and FTIR spectroscopy

“…The consequence is lower pollen germination potency (Lahlali et al 2014; Jiang et al 2015). Pollen lipids play also an important role in the induction and the strengthening of allergy (Risse et al 2000).…”

“…They could alter the allergenic properties of proteins and modify the immune response (Bashir et al 2013). Lipids content and their quantitative changes can be easily detected by infrared spectroscopy (Jiang et al 2015). Zimmermann and Kohler (2014) found the change in infrared spectra at the peak corresponding to lipids (1745 cm −1 ) in pollen collected from the site with high temperatures.…”

“…High resolution, fast measurements, low cost, and minimal material preparation are some of the many advantages of this method (Pappas et al 2003; Zimmermann 2010; Zimmermann and Kohler 2014; Zimmermann et al 2016). For these reasons, FTIR spectroscopy is being increasingly used in the fields of agriculture, biology, ecology, biochemistry, and medicine (Movasaghia et al 2008; Rubio-Diaz et al 2010; Singh et al 2012; Jiang et al 2015; Depciuch et al 2016a, b). This method was also applied in palynology as an effective tool in phylogenetic taxonomy (Pappas et al 2003, Gottardini et al 2007; Zimmermann 2010; Zimmermann and Kohler, 2014; Bağcıoğlu et al 2015).…”