An interspecific hybrid F1 of Cucumis hystrix Chakr. x Cucumis sativus L. （NC4406） was used to establish the developmental sequence and to characterize the male and female gametophytes at cytological level for furth...An interspecific hybrid F1 of Cucumis hystrix Chakr. x Cucumis sativus L. （NC4406） was used to establish the developmental sequence and to characterize the male and female gametophytes at cytological level for further understanding of the phylogenic relationship and the mechanism of fertility or sterility in the interspecific hybrid F1 The development of male and female gametophytes was studied through meiotic analysis and paraffin section observation technique, respectively. Meanwhile, the fertility level was assessed through hybrid F1 backcrossing to cultivated cucumber 4406. Variable chromosome configurations were observed in the pollen mother cells （PMCs） of hybrid F1 at metaphase Ⅰ , e.g., univalents, bivalents, trivalents, quadravalents, etc. At anaphase Ⅰ and Ⅱ, chromosome lagging and bridges were frequently observed as well, which led to the formation of polyads and only a partial number of microspores could develop into fertile pollen grains （about 23.3%）. Observations of the paraffin sections showed numerous degenerated and abnormal embryo sacs during the development of female gametophytes, and only 40% of the female gametophytes could develop into normal eight-nuclear megaspore. On an average, 22.8 and 6.3 seeds per fruit could be obtained from the reciprocal backcross. The interspecific hybrid F1 of C. hystrix x NC4406 was partially fertile; however, the meiotic behaviors of hybrid F1 showed a high level of intergenomic recombination between C. hystrix and C. sativus chromosomes, which indicated that it plays an important role for introgression of useful traits from C. hystrix into C. sativus.展开更多
Nodulin 26-like intrinsic proteins(NIPs) are a family of channel-forming transmembrane proteins that function in the transport of water and other small molecules.Some NIPs can mediate silicon transport across plasma m...Nodulin 26-like intrinsic proteins(NIPs) are a family of channel-forming transmembrane proteins that function in the transport of water and other small molecules.Some NIPs can mediate silicon transport across plasma membranes and lead to silicon accumulation in plants,which is beneficial for the growth and development of plants.Cucumber is one of the most widely consumed vegetables;however,the functions of NIPs in this crop are still largely unknown.Here,we report the functional characteristics of Cs NIP2;2.It was found that Cs NIP2;2 is a tandem repeat of Cs NIP2;1,which had been demonstrated to be a silicon influx transporter gene.Cs NIP2;2 has a selectivity filter composed of cysteine,serine,glycine and arginine(CSGR),which is different from all previously characterized silicon influx transporters in higher plants at the second helix position.Xenopus laevis oocytes injected with Cs NIP2;2 c RNA demonstrated a higher uptake of silicon than the control,and the uptake remained unchanged under low temperature.Cs NIP2;2 was found to be expressed in the root,stem,lamina and petiole,and exogenous silicon treatment decreased its expression in the stem but not in other tissues.Transient expression of Cs NIP2;2-e GFP fusion sequence in onion epidermal cells showed that Cs NIP2;2 was localized to the cell nucleus,plasma membrane and an unknown structure inside the cell.The results suggest that Cs NIP2;2 is a silicon influx transporter in cucumber,and its subcellular localization and the selectivity filter are different from those of the previously characterized silicon influx transporters in other plants.These findings may be helpful for understanding the functions of NIPs in cucumber plants.展开更多
Employing nutrient solution hydroponic method,the effects of exogenous nitric oxide（NO）on the growth and active oxygen metabolism in cucumber（Cucumis sativus L.）seedlings under NaCl stress were investigated.The re...Employing nutrient solution hydroponic method,the effects of exogenous nitric oxide（NO）on the growth and active oxygen metabolism in cucumber（Cucumis sativus L.）seedlings under NaCl stress were investigated.The results indicated that NaCl treatment significantly inhibited the growth of cucumber seedlings,while exogenous NO could significantly alleviate the inhibitory effects of NaCl stress on seedling growth.Especially,0.1 mmol/L SNP treatment exhibited better effects than 0.5 mmol/L SNP treatment on alleviating NaCl stress.Under 0.1 mmol/L NaCl stress,adding 0.1 mmol/L exogenous NO could significantly decrease the generation rate of O·-2and MDA content,significantly improve soluble protein content and enhance the activities of SOD,POD and CAT,thus reducing the damage of salt stress to cucumber seedlings.展开更多
基金This paper is translated from its Chinese version in Scientia Agricultura Sinica.This research was partially supported by the Transcentury Training Program Foundation for the Talents by the Ministry of Education of China to Dr.Chen Jinfeng(30470120)by the National Natural Science Foundation of China(30671419)+2 种基金the National Hi-Tech R&D Program(2004AA241120)the Tang Foundation Cornell-China Scholar Programthe Pickle Seed Research Foundation of Pickle Packers International.The authors sincerely thank Dr.Zhai Huqu,the President of the Chinese Academy of Agricultural Sciences for his support in this research.
文摘An interspecific hybrid F1 of Cucumis hystrix Chakr. x Cucumis sativus L. （NC4406） was used to establish the developmental sequence and to characterize the male and female gametophytes at cytological level for further understanding of the phylogenic relationship and the mechanism of fertility or sterility in the interspecific hybrid F1 The development of male and female gametophytes was studied through meiotic analysis and paraffin section observation technique, respectively. Meanwhile, the fertility level was assessed through hybrid F1 backcrossing to cultivated cucumber 4406. Variable chromosome configurations were observed in the pollen mother cells （PMCs） of hybrid F1 at metaphase Ⅰ , e.g., univalents, bivalents, trivalents, quadravalents, etc. At anaphase Ⅰ and Ⅱ, chromosome lagging and bridges were frequently observed as well, which led to the formation of polyads and only a partial number of microspores could develop into fertile pollen grains （about 23.3%）. Observations of the paraffin sections showed numerous degenerated and abnormal embryo sacs during the development of female gametophytes, and only 40% of the female gametophytes could develop into normal eight-nuclear megaspore. On an average, 22.8 and 6.3 seeds per fruit could be obtained from the reciprocal backcross. The interspecific hybrid F1 of C. hystrix x NC4406 was partially fertile; however, the meiotic behaviors of hybrid F1 showed a high level of intergenomic recombination between C. hystrix and C. sativus chromosomes, which indicated that it plays an important role for introgression of useful traits from C. hystrix into C. sativus.
基金supported by the National Key Research and Development Program of China (2018YFD1000800)the National Natural Science Foundation of China (32072561 and 31772290)。
文摘Nodulin 26-like intrinsic proteins(NIPs) are a family of channel-forming transmembrane proteins that function in the transport of water and other small molecules.Some NIPs can mediate silicon transport across plasma membranes and lead to silicon accumulation in plants,which is beneficial for the growth and development of plants.Cucumber is one of the most widely consumed vegetables;however,the functions of NIPs in this crop are still largely unknown.Here,we report the functional characteristics of Cs NIP2;2.It was found that Cs NIP2;2 is a tandem repeat of Cs NIP2;1,which had been demonstrated to be a silicon influx transporter gene.Cs NIP2;2 has a selectivity filter composed of cysteine,serine,glycine and arginine(CSGR),which is different from all previously characterized silicon influx transporters in higher plants at the second helix position.Xenopus laevis oocytes injected with Cs NIP2;2 c RNA demonstrated a higher uptake of silicon than the control,and the uptake remained unchanged under low temperature.Cs NIP2;2 was found to be expressed in the root,stem,lamina and petiole,and exogenous silicon treatment decreased its expression in the stem but not in other tissues.Transient expression of Cs NIP2;2-e GFP fusion sequence in onion epidermal cells showed that Cs NIP2;2 was localized to the cell nucleus,plasma membrane and an unknown structure inside the cell.The results suggest that Cs NIP2;2 is a silicon influx transporter in cucumber,and its subcellular localization and the selectivity filter are different from those of the previously characterized silicon influx transporters in other plants.These findings may be helpful for understanding the functions of NIPs in cucumber plants.
基金Supported by Independent Innovation Project of Jiangsu Province[CX(11)1005]Nanjing Science and Technology Development Project(2011ZD006)
文摘Employing nutrient solution hydroponic method,the effects of exogenous nitric oxide（NO）on the growth and active oxygen metabolism in cucumber（Cucumis sativus L.）seedlings under NaCl stress were investigated.The results indicated that NaCl treatment significantly inhibited the growth of cucumber seedlings,while exogenous NO could significantly alleviate the inhibitory effects of NaCl stress on seedling growth.Especially,0.1 mmol/L SNP treatment exhibited better effects than 0.5 mmol/L SNP treatment on alleviating NaCl stress.Under 0.1 mmol/L NaCl stress,adding 0.1 mmol/L exogenous NO could significantly decrease the generation rate of O·-2and MDA content,significantly improve soluble protein content and enhance the activities of SOD,POD and CAT,thus reducing the damage of salt stress to cucumber seedlings.
