scholarly journals Two Expansin Genes, AtEXPA4 and AtEXPB5, Are Redundantly Required for Pollen Tube Growth and AtEXPA4 Is Involved in Primary Root Elongation in Arabidopsis thaliana

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 249
Author(s):  
Weimiao Liu ◽  
Liai Xu ◽  
Hui Lin ◽  
Jiashu Cao

The growth of plant cells is inseparable from relaxation and expansion of cell walls. Expansins are a class of cell wall binding proteins, which play important roles in the relaxation of cell walls. Although there are many members in expansin gene family, the functions of most expansin genes in plant growth and development are still poorly understood. In this study, the functions of two expansin genes, AtEXPA4 and AtEXPB5 were characterized in Arabidopsis thaliana. AtEXPA4 and AtEXPB5 displayed consistent expression patterns in mature pollen grains and pollen tubes, but AtEXPA4 also showed a high expression level in primary roots. Two single mutants, atexpa4 and atexpb5, showed normal reproductive development, whereas atexpa4atexpb5 double mutant was defective in pollen tube growth. Moreover, AtEXPA4 overexpression enhanced primary root elongation, on the contrary, knocking out AtEXPA4 made the growth of primary root slower. Our results indicated that AtEXPA4 and AtEXPB5 were redundantly involved in pollen tube growth and AtEXPA4 was required for primary root elongation.

Genetics ◽  
2001 ◽  
Vol 158 (4) ◽  
pp. 1773-1783 ◽  
Author(s):  
Antonia Procissi ◽  
Solveig de Laissardière ◽  
Madina Férault ◽  
Daniel Vezon ◽  
Georges Pelletier ◽  
...  

Abstract Mutant analysis represents one of the most reliable approaches to identifying genes involved in plant development. The screening of the Versailles collection of Arabidopsis thaliana T-DNA insertion transformants has allowed us to isolate different mutations affecting male gametophytic functions and viability. Among several mutated lines, five have been extensively studied at the genetic, molecular, and cytological levels. For each mutant, several generations of selfing and outcrossing have been carried out, leading to the conclusion that all these mutations are tagged and affect only the male gametophyte. However, only one out of the five mutations is completely penetrant. A variable number of T-DNA copies has integrated in the mutant lines, although all segregate at one mutated locus. Two mutants could be defined as “early mutants”: the mutated genes are presumably expressed during pollen grain maturation and their alteration leads to the production of nonfunctional pollen grains. Two other mutants could be defined as “late mutant” since their pollen is able to germinate but pollen tube growth is highly disturbed. Screening for segregation ratio distortions followed by thorough genetic analysis proved to be a powerful tool for identifying gametophytic mutations of all phases of pollen development.


Author(s):  
Laetitia Poidevin ◽  
Javier Forment ◽  
Dilek Unal ◽  
Alejandro Ferrando

ABSTRACTPlant reproduction is one key biological process very sensitive to heat stress and, as a consequence, enhanced global warming poses serious threats to food security worldwide. In this work we have used a high-resolution ribosome profiling technology to study how heat affects both the transcriptome and the translatome of Arabidopsis thaliana pollen germinated in vitro. Overall, a high correlation between transcriptional and translational responses to high temperature was found, but specific regulations at the translational level were also present. We show that bona fide heat shock genes are induced by high temperature indicating that in vitro germinated pollen is a suitable system to understand the molecular basis of heat responses. Concurrently heat induced significant down-regulation of key membrane transporters required for pollen tube growth, thus uncovering heat-sensitive targets. We also found that a large subset of the heat-repressed transporters is specifically up-regulated, in a coordinated manner, with canonical heat-shock genes in pollen tubes grown in vitro and semi in vivo, based on published transcriptomes from Arabidopsis thaliana. Ribosome footprints were also detected in gene sequences annotated as non-coding, highlighting the potential for novel translatable genes and translational dynamics.


2014 ◽  
Vol 65 (1-2) ◽  
pp. 101-105 ◽  
Author(s):  
Renata Śnieżko ◽  
Krystyna Winiarczyk

After selfpollination of <em>Sinapis alba</em> L. pollen tubes growth is inhibited on the stigma. The pollen grains germinate 3-4 hours after pollination. The pollen give rise to one or more pollen tubes. They grow along the papillae. In the place of contact between the papilla and pollen tube the pellicula is digested. Then the direction of pollen tube growth changes completely. Pollen tubes grow back on the exine of their own pollen grain, or turn into the air. The pollen tubes growth was inhibited in 6-8 hours after selfpollination. After crosspollination usually there is no incompatibility reaction.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Ferdousse Laggoun ◽  
Flavien Dardelle ◽  
Jérémy Dehors ◽  
Denis Falconet ◽  
Azeddine Driouich ◽  
...  

2008 ◽  
Vol 35 (2) ◽  
pp. 152 ◽  
Author(s):  
Kanjana Luangsuwalai ◽  
Saichol Ketsa ◽  
Apinya Wisutiamonkul ◽  
Wouter G. van Doorn

Dendrobium flowers, pollinated with pollinia from individuals of the same cultivar or other cultivars, usually show rapid post-pollination effects such as floral epinasty, a change in flower colour and early perianth senescence. However, pollination with the pollinia of cv. Karen or cv. Kenny flowers did not produce these effects. We compared these two cultivars with cvv. Pompadour, Willie and Sakura, and tested the hypotheses that the differences were related to levels of 1-aminocyclopropane-1-carboxylic acid (ACC) in the pollinia, ethylene production by the pollinated flower, pollen germination, or pollen tube growth. The pollinia of cvv. Karen and Kenny contained as much ACC as the pollinia of cv. Pompadour, but less than the pollinia of cvv. Willie and Sakura. Ethylene production after pollination with cvv. Karen and Kenny pollinia was much lower than after pollination with pollinia from the other cultivars tested. The pollen grains showed normal germination, but cvv. Karen and Kenny pollen grains exhibited much less tube growth than those of the other cultivars. Pollen tube growth in cv. Pompadour was positively affected by ethylene. Ethylene was required and sufficient for the induction of epinasty, rapid perianth colour changes and early perianth senescence, very similar to the changes after pollination. The absence of these effects after pollination with cvv. Kenny and Karen seems to be due to the low ethylene production induced by the pollinia of these cultivars. This low ethylene production could not be accounted for by the ACC content in the pollinia of cvv. Kenny and Karen.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260576
Author(s):  
Massaine Bandeira e Sousa ◽  
Luciano Rogerio Braatz de Andrade ◽  
Everton Hilo de Souza ◽  
Alfredo Augusto Cunha Alves ◽  
Eder Jorge de Oliveira

Cassava breeding is hampered by high flower abortion rates that prevent efficient recombination among promising clones. To better understand the factors causing flower abortion and propose strategies to overcome them, we 1) analyzed the reproductive barriers to intraspecific crossing, 2) evaluated pollen-pistil interactions to maximize hand pollination efficiency, and 3) identified the population structure of elite parental clones. From 2016 to 2018, the abortion and fertilization rates of 5,748 hand crossings involving 91 parents and 157 progenies were estimated. We used 16,300 single nucleotide polymorphism markers to study the parents’ population structure via discriminant analysis of principal components, and three clusters were identified. To test for male and female effects, we used a mixed model in which the environment (month and year) was fixed, while female and male (nested to female) were random effects. Regardless of the population structure, significant parental effects were identified for abortion and fertilization rates, suggesting the existence of reproductive barriers among certain cassava clones. Matching ability between cassava parents was significant for pollen grains that adhered to the stigma surface, germinated pollen grains, and the number of fertilized ovules. Non-additive genetic effects were important to the inheritance of these traits. Pollen viability and pollen-pistil interactions in cross- and self-pollination were also investigated to characterize pollen-stigma compatibility. Various events related to pollen tube growth dynamics indicated fertilization abnormalities. These abnormalities included the reticulated deposition of callose in the pollen tube, pollen tube growth cessation in a specific region of the stylet, and low pollen grain germination rate. Generally, pollen viability and stigma receptivity varied depending on the clone and flowering stage and were lost during flowering. This study provides novel insights into cassava reproduction that can assist in practical crossing and maximize the recombination of contrasting clones.


2013 ◽  
Vol 6 (4) ◽  
pp. 1355-1357 ◽  
Author(s):  
Regina Scarpin ◽  
Lorena Sigaut ◽  
Lia Pietrasanta ◽  
Sheila McCormick ◽  
Binglian Zheng ◽  
...  

1968 ◽  
Vol 46 (3) ◽  
pp. 235-240 ◽  
Author(s):  
P. L. Pfahler

Pollen grains from six single cross hybrids (Wf9 × H55, Wf9 × H50, H49 × H55, H49 × H50, Ky49 × Ky27, and K64 × K55) of Zea mays L. were cultured on an artificial medium containing 15% sucrose and 0.6% bacto-agar supplemented with all possible combinations of two levels (0.00 and 0.03%) of calcium nitrate (Ca) and two levels (0.00 and 0.01%) of boric acid (B). The effect of Ca and B on germination percentage was found to be dependent on the genetic source of the pollen. At the 0.00% levels of Ca and B, the germination percentage of the hybrids ranged from 26.6% for Ky49 × Ky27 to 58.1% for K64 × K55. With either Ky49 × Ky27 or K64 × K55 pollen, the addition of Ca and B to the medium resulted in a lower germination percentage whereas the addition of Ca and B increased the germination percentage of the other hybrids. The addition of B in the absence of Ca sharply reduced the germination percentage in all hybrids while in the presence of Ca, the effect of B varied with the hybrid involved. For pollen tube length, highly significant interactions between hybrids and levels of Ca and B were found. However, maximum pollen tube lengths were obtained for all hybrids with both Ca and B in the medium. The addition of B in the absence of Ca reduced the pollen tube length of all hybrids whereas the addition of B in the presence of Ca increased pollen tube length. In general, the addition of both Ca and B increased the rate of pollen tube growth especially in the period 2 to 3 hours after inoculation.


Author(s):  
Heidi Pertl-Obermeyer ◽  
Ana Gimeno ◽  
Verena Kuchler ◽  
Evrim Servili ◽  
Shuai Huang ◽  
...  

Abstract Pollen grains transport the sperm cells through the style tissue via a fast-growing pollen tube to the ovaries where fertilization takes place. Pollen tube growth requires a precisely regulated network of cellular as well as molecular events including the activity of the plasma membrane H+ ATPase, which is known to be regulated by reversible protein phosphorylation and subsequent binding of 14-3-3 isoforms. Immunodetection of the phosphorylated penultimate threonine residue of the pollen plasma membrane H+ ATPase (LilHA1) of Lilium longiflorum pollen revealed a sudden increase in phosphorylation with the start of pollen tube growth. In addition to phosphorylation, pH modulated the binding of 14-3-3 isoforms to the regulatory domain of the H+ ATPase, whereas metabolic components had only small effects on 14-3-3 binding, as tested with in vitro assays using recombinant 14-3-3 isoforms and phosphomimicking substitutions of the threonine residue. Consequently, local H+ influxes and effluxes as well as pH gradients in the pollen tube tip are generated by localized regulation of the H+ ATPase activity rather than by heterogeneous localized distribution in the plasma membrane.


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