{"title":"Methionine adenosyltransferase MAT3 positively regulates pear pollen tube growth, possibly through interaction with pectin lyase-like protein PLL1.","authors":"Xiaoxuan Zhu, Ting Zhang, Chao Tang, Zhiqi Wang, Lin Guo, Peng Wang, Shaoling Zhang, Juyou Wu","doi":"10.1111/ppl.70122","DOIUrl":null,"url":null,"abstract":"<p><p>Methionine adenosyltransferase (MAT) is the only enzyme that synthesises S-adenosylmethionine (SAM) from ATP and methionine in organisms. While MAT has been extensively studied in plant development and responses to abiotic stress, its role in plant fertilization, particularly in pear pollen tube growth, has been scarcely researched. Here, we demonstrate that the homologous gene of AtMAT3 in pear, PbrMAT3, is positively involved in pear pollen tube elongation. PbrMAT3 is predominantly expressed in pear pollen. Transient knockdown of PbrMAT3 inhibits pollen tube growth. Ethionine, a toxic methionine analogue, suppressed pollen tube growth in control samples but had no inhibitory effect on PbrMAT3-knockdown pollen tubes, suggesting increased methionine accumulation in the latter. However, this accumulation is not responsible for the observed growth inhibition. PbrMAT3 interacts with a pectin lyase-like protein, PbrPLL1, both in vivo and in vitro. Transient knockdown of PbrPLL1 promotes pollen tube growth, suggesting its negative role in pear pollen tube elongation. Additionally, the pectate lyase activity of the pear pollen tube was increased when PbrMAT3 was knocked down. Thus, the inhibition of pollen tube growth due to PbrMAT3 knockdown is not caused by methionine accumulation but may be mediated by PbrPLL1. This study provides new insight into the relationship between S-adenosylmethionine synthesis and pollen tube growth.</p>","PeriodicalId":20164,"journal":{"name":"Physiologia plantarum","volume":"177 1","pages":"e70122"},"PeriodicalIF":5.4000,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physiologia plantarum","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1111/ppl.70122","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Methionine adenosyltransferase (MAT) is the only enzyme that synthesises S-adenosylmethionine (SAM) from ATP and methionine in organisms. While MAT has been extensively studied in plant development and responses to abiotic stress, its role in plant fertilization, particularly in pear pollen tube growth, has been scarcely researched. Here, we demonstrate that the homologous gene of AtMAT3 in pear, PbrMAT3, is positively involved in pear pollen tube elongation. PbrMAT3 is predominantly expressed in pear pollen. Transient knockdown of PbrMAT3 inhibits pollen tube growth. Ethionine, a toxic methionine analogue, suppressed pollen tube growth in control samples but had no inhibitory effect on PbrMAT3-knockdown pollen tubes, suggesting increased methionine accumulation in the latter. However, this accumulation is not responsible for the observed growth inhibition. PbrMAT3 interacts with a pectin lyase-like protein, PbrPLL1, both in vivo and in vitro. Transient knockdown of PbrPLL1 promotes pollen tube growth, suggesting its negative role in pear pollen tube elongation. Additionally, the pectate lyase activity of the pear pollen tube was increased when PbrMAT3 was knocked down. Thus, the inhibition of pollen tube growth due to PbrMAT3 knockdown is not caused by methionine accumulation but may be mediated by PbrPLL1. This study provides new insight into the relationship between S-adenosylmethionine synthesis and pollen tube growth.
期刊介绍:
Physiologia Plantarum is an international journal committed to publishing the best full-length original research papers that advance our understanding of primary mechanisms of plant development, growth and productivity as well as plant interactions with the biotic and abiotic environment. All organisational levels of experimental plant biology – from molecular and cell biology, biochemistry and biophysics to ecophysiology and global change biology – fall within the scope of the journal. The content is distributed between 5 main subject areas supervised by Subject Editors specialised in the respective domain: (1) biochemistry and metabolism, (2) ecophysiology, stress and adaptation, (3) uptake, transport and assimilation, (4) development, growth and differentiation, (5) photobiology and photosynthesis.