Identification and characterization of TcCRP1, a pollen tube attractant from Torenia concolor

Abstract

The results indicated that this class of CRP proteins is a common pollen tube attractant in Torenia species. The sequence diversity of these proteins is important for species-specific pollen tube attraction.

Species-specific interaction of EA1 with the maize pollen tube apex

“…In the eudicot model plant Torenia fournieri cysteine-rich defensin-like proteins were identified as LUREs to attract own pollen tubes in a species-preferential manner 6 . LUREs have been identified recently also in Torenia concolor (TcCRP1) and in Arabidopsis species (AtLURE1 and AlLURE1) 7 , 8 . In a recent publication we could show that EA1 acts as a species-preferential direct attractant of maize pollen tubes in vitro.…”

Gametophytic Pollen Tube Guidance: Attractant Peptides, Gametic Controls, and Receptors

“…1B). In dicot plant species such as Torenia and Arabidopsis, defensinlike CRPs known as LUREs are secreted as pollen tube attractants (Okuda et al, 2009;Kanaoka et al, 2011;Takeuchi and Higashiyama, 2012; putatively 60-70 amino acids). In maize, on the other hand, the EGG AP-PARATUS1 (ZmEA1) peptide has been reported to be a pollen tube attractant (Márton et al, 2005(Márton et al, , 2012; putatively 49 amino acids; non CRP).…”

“…One of the important aspects of pollen tube attractants derived from synergid cells is strong species preferentiality and specificity (Okuda et al, 2009;Kanaoka et al, 2011;Márton et al, 2012;Takeuchi and Higashiyama, 2012). Micropylar pollen tube attraction in the semi-in vitro system is species preferential (pollen tubes preferentially grow toward ovules of their own species) even in closely related species, such as between Torenia and Torenia conclor/Torenia billonii (Higashiyama et al, 2006).…”

“…The tertiary structures of LUREs and ZmEA1 peptides have not been solved, while those of some other CRPs, including Raphanus sativus ANTIFUNGAL PROTEIN1 (Fant et al, 1998), SCR/SP11 (Mishima et al, 2003), STOMAGEN (Ohki et al, 2011), and ESF1 (Costa et al, 2014), have been solved. During the evolution of Torenia (Kanaoka et al, 2011) and Arabidopsis (Takeuchi and Higashiyama, 2012), amino acid substitutions of LUREs occurred throughout the peptides. However, it is possible that specific regions of LURE peptides might be important for species-specific recognition, as is the case for SCR/SP11 (Mishima et al, 2003) and STOMAGEN (Ohki et al, 2011).…”

Green love talks; cell–cell communication during double fertilization in flowering plants

“…Micropylar guidance attractants such as LUREs and ZmEA1 belong to highly polymorphic families, and indeed LUREs show species preferentiality on pollen tube guidance (Okuda and Higashiyama 2010; Kanaoka et al . 2011).…”