Calreticulin expression and localization in plant cells during pollen–pistil interactions

Lenartowska, Marta; Lenartowski, Robert; Smoliński, Dariusz Jan; Wróbel, Bogdan; Niedojadło, Janusz; Jaworski, Krzysztof; Bednarska, E

doi:10.1007/s00425-009-1024-1

Cited by 20 publications

(43 citation statements)

References 60 publications

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“…Similarly, the transcripts of CRTs are detected in pollen grains, pollen tubes, and pistils in Haemanthus (Lenartowska et al, 2009). Together, these data suggest that POD1 most likely interacts with CRT3 and plays an important role in ER quality control.…”

Section: Pod1 Interacts With Crt3mentioning

confidence: 89%

POD1 Regulates Pollen Tube Guidance in Response to Micropylar Female Signaling and Acts in Early Embryo Patterning inArabidopsis

Xue

Jia

et al. 2011

The Plant Cell

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The pollen tube germinates from pollen and, during its migration, it perceives and responds to guidance cues from maternal tissue and from the female gametophyte. The putative female cues have recently been identified, but how the pollen tube responds to these signals remains to be unveiled. In a genetic screen for male determinants of the pollen tube response, we identified the pollen defective in guidance1 (pod1) mutant, in which the pollen tubes fail to target the female gametophyte. POD1 encodes a conserved protein of unknown function and is essential for positioning and orienting the cell division plane during early embryo development. Here, we demonstrate that POD1 is an endoplasmic reticulum (ER) luminal protein involved in ER protein retention. Further analysis shows that POD1 interacts with the Ca2+ binding ER chaperone CALRETICULIN3 (CRT3), a protein in charge of folding of membrane receptors. We propose that POD1 modulates the activity of CRT3 or other ER resident factors to control the folding of proteins, such as membrane proteins in the ER. By this mechanism, POD1 may regulate the pollen tube response to signals from the female tissues during pollen tube guidance and early embryo patterning in Arabidopsis thaliana.

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Section: Pod1 Interacts With Crt3mentioning

confidence: 89%

POD1 Regulates Pollen Tube Guidance in Response to Micropylar Female Signaling and Acts in Early Embryo Patterning inArabidopsis

Xue

Jia

et al. 2011

The Plant Cell

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“…Additionally, high levels of CRT and its transcripts were detected in developing tobacco anthers, especially in pollen tetrads and in the active tapetum, as well as in dry, hydrated, and germinating pollen and growing tubes (Nardi et al 2006). Finally, we observed strong CRT expression in germinated pollen and elongated tubes of Haemanthus (Lenartowska et al 2009) and Petunia (Lenartowska et al 2001, 2002; Lenartowski et al 2014, 2015). On the basis of our findings, we speculated that CRT is translated on ER-associated ribosomes in germinating pollen and growing tubes.…”

Section: Introductionmentioning

confidence: 63%

“…For example, the ER lumen in Arabidopsis pollen tubes sequesters high levels of Ca 2+ (Iwano et al 2009), and both auto inhibited Ca 2+ ATPases and ER-type Ca 2+ ATPases are present in pollen (see review by Sze et al 2006). Additionally, studies in Petunia (Lenartowska et al 2002; Lenartowski et al 2015), Nicotiana (Nardi et al 2006), and Haemanthus (Lenartowska et al 2009) indicate that the ER of pollen tubes contains CRT, which is a prominent Ca 2+ buffer in eukaryotic cells (see review by Jia et al 2009; Michalak et al 2009). …”

Section: Introductionmentioning

confidence: 99%

Molecular evidence that rough endoplasmic reticulum is the site of calreticulin translation in Petunia pollen tubes growing in vitro

et al. 2015

Self Cite

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Key messageIn germinating pollen grains and growing pollen tubes, CRT is translated on ER membrane-bound ribosomes in the regions where its activity is required for stabilization of tip-focused Ca2+gradient.AbstractPollen tube growth requires coordination of signaling, exocytosis, and actin cytoskeletal organization. Many of these processes are thought to be controlled by finely tuned regulation of cytoplasmic Ca2+ in discrete regions of the tube cytoplasm. Most notably, a mechanism must function to maintain a steep gradient of Ca2+ that exists at the tip of growing pollen tube. Several pieces of evidence point to calreticulin (CRT) as a key Ca2+-binding/-buffering protein involved in pollen germination and pollen tube growth. We previously hypothesized that in germinating pollen and growing tubes, CRT is translated on the ribosomes associated with endoplasmic reticulum (ER) in the regions where its activity might be required. In this report, we have addressed this idea by identifying the sites where CRT mRNA, CRT protein, 18S rRNA, and rough ER are localized in Petunia pollen tubes. We observed all four components in the germinal aperture of pollen grains and in subapical regions of elongating tubes. These results seem to support our idea that CRT is translated on ER membrane-bound ribosomes during pollen germination and pollen tube growth. In elongated pollen tubes, we found CRT mainly localized in the subapical zone, where ER and Golgi stacks are abundant. In eukaryotic cells, these organelles serve as mobile intracellular stores of easily releasable Ca2+, which can be buffered by proteins such as CRT. Therefore, we postulate that subapical-localized CRT is involved in pollen tube growth by maintaining the stable tip-focused Ca2+ gradient and thus modulating local Ca2+ concentration within the tube cytoplasm.

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“…Although many regulators of Ca 2+ dynamics and effectors of Ca 2+ signaling have been identified during pollen tube growth regulation, the regulatory mechanism for Ca 2+ in pollination remains to be elucidated. Lenartowska et al (2009) reported that calreticulins, proteins involved in cellular Ca 2+ homeostasis regulation, could be detected in the pollen/pollen tubes and the transmitting tract of pollinated pistil of Haemanthus, suggesting a possible role for these proteins in pollen-pistil interaction. Additionally, reactive oxygen species and nitric oxide (NO) signaling were found to be involved in pollen-stigma interaction, and NO exerts its role by modulating Ca 2+ signaling (McInnis et al, 2006;Hiscock and Allen, 2008;Prado et al, 2008).…”

Section: Stigma Signaling In the Pollen-stigma Interactionmentioning

confidence: 99%

Stigma factors regulating self-compatible pollination

2010

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Pollination is one of the most important steps during fertilization and sexual reproduction in plants, and numerous cell-cell interaction events occur between the pistil and the pollen grain/tube during this process. The pollen-stigma interaction is a highly selective process which leads to compatible or incompatible pollination. Previous studies in Solanaceae, Papaveraceae, and Brassicaceae provided some important insights into pollen-stigma recognition in self-incompatible systems. In recent years, considerable data have been available regarding pollen-stigma interaction during self-compatible pollination. In this review, we focus on discussing current knowledge on stigma factors that regulate pollen-stigma interaction in self-compatible systems in comparison with self-incompatible systems.

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Calreticulin expression and localization in plant cells during pollen–pistil interactions

Cited by 20 publications

References 60 publications

POD1 Regulates Pollen Tube Guidance in Response to Micropylar Female Signaling and Acts in Early Embryo Patterning inArabidopsis

POD1 Regulates Pollen Tube Guidance in Response to Micropylar Female Signaling and Acts in Early Embryo Patterning inArabidopsis

Molecular evidence that rough endoplasmic reticulum is the site of calreticulin translation in Petunia pollen tubes growing in vitro

Stigma factors regulating self-compatible pollination

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