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Developmental and heat stress-regulated expression of HsfA2 and small heat shock proteins in tomato anthers.

Giorno F, Wolters-Arts M, Grillo S, Scharf KD, Vriezen WH, Mariani C - J. Exp. Bot. (2009)

Bottom Line: A transcriptional analysis at different developmental anther/pollen stages was performed using semi-quantitative and real-time PCR.The messengers were localized using in situ RNA hybridization, and protein accumulation was monitored using immunoblot analysis.These data suggest that HsfA2 may be directly involved in the activation of protection mechanisms in the tomato anther during heat stress and, thereby, may contribute to tomato fruit set under adverse temperatures.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Cell Biology, IWWR Institute, Radboud University Nijmegen, Heyendaalseweg 135, Nijmegen, The Netherlands.

ABSTRACT
The high sensitivity of male reproductive cells to high temperatures may be due to an inadequate heat stress response. The results of a comprehensive expression analysis of HsfA2 and Hsp17-CII, two important members of the heat stress system, in the developing anthers of a heat-tolerant tomato genotype are reported here. A transcriptional analysis at different developmental anther/pollen stages was performed using semi-quantitative and real-time PCR. The messengers were localized using in situ RNA hybridization, and protein accumulation was monitored using immunoblot analysis. Based on the analysis of the gene and protein expression profiles, HsfA2 and Hsp17-CII are finely regulated during anther development and are further induced under both short and prolonged heat stress conditions. These data suggest that HsfA2 may be directly involved in the activation of protection mechanisms in the tomato anther during heat stress and, thereby, may contribute to tomato fruit set under adverse temperatures.

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Transcriptional changes of HsfA2 and Hsp 17.4-CII in tomato tissues under HS. Total flower tissues at anthesis and leaf tissues were harvested from cv Saladette treated with daily repeated cycles of mild HS and recovery for 3 weeks (HS: 36 °C / 26 °C, day/night) or maintained under control conditions (CT: 26 °C / 19 °C day/night). From these same treated and untreated plants, flowers harvested at anthesis were dissected into sepal, petal, anther, and pistil. (A) Semi-quantitative PCR shows increased mRNA levels of HsfA2 and Hsp17.4-CII in tomato flowers and leaves under prolonged HS conditions. (B) Relative transcript levels of HsfA2 were measured by qRT-PCR using LeEF1 and 18S rRNA as housekeeping genes to normalize the data. The highest induction of HsfA2 was identified in the anther tissues treated at high temperatures. (C) A similar transcript profile to that of (B) was also observed for Hsp17.4-CII, which was strongly induced in the male reproductive organs under HS.
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fig1: Transcriptional changes of HsfA2 and Hsp 17.4-CII in tomato tissues under HS. Total flower tissues at anthesis and leaf tissues were harvested from cv Saladette treated with daily repeated cycles of mild HS and recovery for 3 weeks (HS: 36 °C / 26 °C, day/night) or maintained under control conditions (CT: 26 °C / 19 °C day/night). From these same treated and untreated plants, flowers harvested at anthesis were dissected into sepal, petal, anther, and pistil. (A) Semi-quantitative PCR shows increased mRNA levels of HsfA2 and Hsp17.4-CII in tomato flowers and leaves under prolonged HS conditions. (B) Relative transcript levels of HsfA2 were measured by qRT-PCR using LeEF1 and 18S rRNA as housekeeping genes to normalize the data. The highest induction of HsfA2 was identified in the anther tissues treated at high temperatures. (C) A similar transcript profile to that of (B) was also observed for Hsp17.4-CII, which was strongly induced in the male reproductive organs under HS.

Mentions: Previous results (F Giorno and S Grillo, unpublished data) suggested that HsfA2 and Hsp17.4-CII genes are induced in response to HS during tomato flower development, particularly at anthesis, when pollination occurs. The expression of these genes in tomato microspores has also been reported (Frank et al., 2009). The influence of HS on the expression of these genes in the flower and during anther development was therefore studied here in more detail. As shown in Fig. 1A, HsfA2 and Hsp17.4-CII were induced in the tissues of flowers at anthesis and in leaves harvested from cv Saladette treated with daily repeated cycles of mild HS and recovery for 3 weeks (HS: 36 °C / 26 °C, day/night). The real-time PCR (qRT-PCR) results showed that HsfA2 and Hsp17.4-CII were more highly induced in the anther than in the other flower tissues (Fig. 1B, C). The observation that both HsfA2 and Hsp17.4-CII were more highly expressed in the tomato male reproductive organs suggests that they may play a role in the protection system of sporophytic and/or sporogenic tissues in the anther. The timing of the activation of this protection system during anther development was investigated here by first determining the transcript levels of HsfA2 and Hsp17.4-CII in 2, 4, 6, and 8 mm long anthers using semi-quantitative PCR (Fig. 2). As shown in Fig. 2B, the transcripts of HsfA2 and Hsp17.4-CII were more detectable during development at the 2 mm stage under CT conditions, while both mRNAs were present at all stages of development after HS for 2 h at 36 °C.


Developmental and heat stress-regulated expression of HsfA2 and small heat shock proteins in tomato anthers.

Giorno F, Wolters-Arts M, Grillo S, Scharf KD, Vriezen WH, Mariani C - J. Exp. Bot. (2009)

Transcriptional changes of HsfA2 and Hsp 17.4-CII in tomato tissues under HS. Total flower tissues at anthesis and leaf tissues were harvested from cv Saladette treated with daily repeated cycles of mild HS and recovery for 3 weeks (HS: 36 °C / 26 °C, day/night) or maintained under control conditions (CT: 26 °C / 19 °C day/night). From these same treated and untreated plants, flowers harvested at anthesis were dissected into sepal, petal, anther, and pistil. (A) Semi-quantitative PCR shows increased mRNA levels of HsfA2 and Hsp17.4-CII in tomato flowers and leaves under prolonged HS conditions. (B) Relative transcript levels of HsfA2 were measured by qRT-PCR using LeEF1 and 18S rRNA as housekeeping genes to normalize the data. The highest induction of HsfA2 was identified in the anther tissues treated at high temperatures. (C) A similar transcript profile to that of (B) was also observed for Hsp17.4-CII, which was strongly induced in the male reproductive organs under HS.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
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getmorefigures.php?uid=PMC2803211&req=5

fig1: Transcriptional changes of HsfA2 and Hsp 17.4-CII in tomato tissues under HS. Total flower tissues at anthesis and leaf tissues were harvested from cv Saladette treated with daily repeated cycles of mild HS and recovery for 3 weeks (HS: 36 °C / 26 °C, day/night) or maintained under control conditions (CT: 26 °C / 19 °C day/night). From these same treated and untreated plants, flowers harvested at anthesis were dissected into sepal, petal, anther, and pistil. (A) Semi-quantitative PCR shows increased mRNA levels of HsfA2 and Hsp17.4-CII in tomato flowers and leaves under prolonged HS conditions. (B) Relative transcript levels of HsfA2 were measured by qRT-PCR using LeEF1 and 18S rRNA as housekeeping genes to normalize the data. The highest induction of HsfA2 was identified in the anther tissues treated at high temperatures. (C) A similar transcript profile to that of (B) was also observed for Hsp17.4-CII, which was strongly induced in the male reproductive organs under HS.
Mentions: Previous results (F Giorno and S Grillo, unpublished data) suggested that HsfA2 and Hsp17.4-CII genes are induced in response to HS during tomato flower development, particularly at anthesis, when pollination occurs. The expression of these genes in tomato microspores has also been reported (Frank et al., 2009). The influence of HS on the expression of these genes in the flower and during anther development was therefore studied here in more detail. As shown in Fig. 1A, HsfA2 and Hsp17.4-CII were induced in the tissues of flowers at anthesis and in leaves harvested from cv Saladette treated with daily repeated cycles of mild HS and recovery for 3 weeks (HS: 36 °C / 26 °C, day/night). The real-time PCR (qRT-PCR) results showed that HsfA2 and Hsp17.4-CII were more highly induced in the anther than in the other flower tissues (Fig. 1B, C). The observation that both HsfA2 and Hsp17.4-CII were more highly expressed in the tomato male reproductive organs suggests that they may play a role in the protection system of sporophytic and/or sporogenic tissues in the anther. The timing of the activation of this protection system during anther development was investigated here by first determining the transcript levels of HsfA2 and Hsp17.4-CII in 2, 4, 6, and 8 mm long anthers using semi-quantitative PCR (Fig. 2). As shown in Fig. 2B, the transcripts of HsfA2 and Hsp17.4-CII were more detectable during development at the 2 mm stage under CT conditions, while both mRNAs were present at all stages of development after HS for 2 h at 36 °C.

Bottom Line: A transcriptional analysis at different developmental anther/pollen stages was performed using semi-quantitative and real-time PCR.The messengers were localized using in situ RNA hybridization, and protein accumulation was monitored using immunoblot analysis.These data suggest that HsfA2 may be directly involved in the activation of protection mechanisms in the tomato anther during heat stress and, thereby, may contribute to tomato fruit set under adverse temperatures.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Cell Biology, IWWR Institute, Radboud University Nijmegen, Heyendaalseweg 135, Nijmegen, The Netherlands.

ABSTRACT
The high sensitivity of male reproductive cells to high temperatures may be due to an inadequate heat stress response. The results of a comprehensive expression analysis of HsfA2 and Hsp17-CII, two important members of the heat stress system, in the developing anthers of a heat-tolerant tomato genotype are reported here. A transcriptional analysis at different developmental anther/pollen stages was performed using semi-quantitative and real-time PCR. The messengers were localized using in situ RNA hybridization, and protein accumulation was monitored using immunoblot analysis. Based on the analysis of the gene and protein expression profiles, HsfA2 and Hsp17-CII are finely regulated during anther development and are further induced under both short and prolonged heat stress conditions. These data suggest that HsfA2 may be directly involved in the activation of protection mechanisms in the tomato anther during heat stress and, thereby, may contribute to tomato fruit set under adverse temperatures.

Show MeSH
Related in: MedlinePlus