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Muscadine grape (Vitis rotundifolia) is highly resistant to many diseases and insects that attack european grape (Vitis vinifera). However, distant hybridization incompatibility between V. rotundifolia (female) and V. vinifera (male) impedes the utilization of V. rotundifolia in grape breeding. This study used fourth-dimension label-free protein quantitation to detect the key genes and pathways in the V. rotundifolia stigma after self-pollination (V. rotundifolia × V. rotundifolia) and cross-pollination (V. rotundifolia × V. vinifera). A histological analysis showed that pollen tube growth in the stigma of V. rotundifolia was arrested 8 hours after cross-pollination, but not after self-pollination. A proteomic analysis identified 32 differentially expressed proteins (DEPs) in the stigma of V. rotundifolia between self-pollination and cross-pollination. A heatmap analysis grouped these DEPs into four clusters. The top gene ontology terms were ATPase-coupled transmembrane transporter activity, extracellular region, DNA replication, and cellular carbohydrate biosynthetic process. A Kyoto Encyclopedia of Genes and Genomes analysis revealed that these DEPs participated in DNA replication and starch and sucrose metabolism pathways. The downregulated A5AY88, D7TJ35, D7SU26, F6HJI1, and F6GUE7 may have a role in cross incompatibility. This study revealed the cross incompatibility of grapes at histological and proteomic levels.
Pistacia chinensis Bunge is a pioneer tree for afforestation, and of high value as an ornament and for timber and medicine. It has also become the preferred biofuel tree in northern China in current years, with a broader development prospect. However, this development is seriously limited due to its dioecious character (separate sexes), because the male (nonfruit) trees are indispensable for pollination, and this leads to a waste of field and low yields. Fortunately, this bottleneck can be broken with the emergence of rare monoecious (having both female and male flowers, and even bisexual flowers) resources in Hebei Province, China. To determine their cultivation characteristics, the variation characteristics and blooming phenophase of local Pistacia were recorded with text, data, and images, by germplasm resources survey, telephone interviews, and field visits. Results showed that 1) 23 monoecious Pistacia were found, with very complex morphological features. 2) The branches of different gender types, ordered by inflorescence length were female > female on monoecious trees > bisexual flowers > inflorescence with male and female > male on monoecious trees > male. Ordered by inflorescence width: female > bisexual flower > female on monoecious trees > inflorescence with male and female > male on monoecious trees > male. Among these, the inflorescence length, inflorescence width, floret diameter, and floret spacing of bisexual flowers were significantly greater than that of male flowers, providing a basis to judge gender type without destructive sampling. 3) Gender types were unstable in successive years—female, male, mixed, or bisexual flowers could convert to another gender within 1 year, except that no female became male, and the overall trend was from male to mixed or bisexual gender in recent years. 4) The blooming phenophase changed a lot among different strains and sex types, which could enlarge the blooming period.
Quantitative trait loci (QTLs) identified so far in Brassica were mainly generated in the final stage of plant development, which did not apply to the exploitation of genetic effects that were expressed during a specific developmental stage. Thus, the objective of this study was to simultaneously identify unconditional and conditional QTL associated with plant height at various stages of nonheading Chinese cabbage. One hundred twelve doubled haploid (DH) lines developed from the cross between nonheading Chinese cabbage lines ‘SW-13’ and ‘SU-124’ were used for QTL analysis of plant height by the composite interval mapping method combined with mixed genetic model. The map we used for QTL analysis was an updated version of the first genetic map of nonheading Chinese cabbage with 48 additional markers to the same DH population. With data from 2 years, a total of 11 unconditional QTLs in six linkage groups and 23 conditional QTLs in eight linkage groups were identified for plant height. The results indicated that the number and type of QTLs and their genetic effects for plant height were different in a series of measuring stages. Each QTL can explain 7.92% to 28.25% of the total phenotypic variation. Two QTLs (ph8-4 and ph8-5) were identified to be associated with plant height using both unconditional and conditional mapping methods simultaneously in 2 years. These results demonstrated that it is highly effective for mapping QTL of developmental traits using the unconditional and conditional analysis methodology.
The objective of the present study was to consider the regulatory role of exogenous nitric oxide (NO) supplementation in response to chilling stress impose alterations on different physiological parameters in melon seedlings. Melon seedlings were treated with sodium nitroprusside (SNP, an NO donor), hemoglobin (a NO scavenger), NG-nitro-L-arginine methyl ester (an NO synthase inhibitor), and tungstate (a nitrite reductase inhibitor) under chilling stress conditions. The results showed that exogenous SNP improves the growth of melon seedlings under chilling stress conditions and ameliorates the harmful effects of chilling stress by increasing the levels of chlorophyll and soluble solutes, elevating the activity of sucrose phosphate synthase by enhancing the expression level of CmSPS. Moreover, exogenous NO significantly enhances the expression of genes and activities of antioxidant enzymes under chilling stress, resulting in lower reactive oxygen species accumulation. However, the protective effects of SNP are reversed by both NO scavenging and inhibition. Collectively, our results reveal that NO has the ability to ameliorate the harmful effects of chilling stress on melon seedlings by regulating carbohydrate metabolism and the antioxidant defense system.
Many reports indicate that an abundance of really interesting new gene (RING) play key roles in regulating defense responses against abiotic and biotic stresses in plants. In this study, the cloning and functional characterization of a RING gene, MaRING2, in banana (Musa acuminata) fruit are reported. MaRING2 belongs to the NEP1-interacting protein (NIP) RING-H2 finger protein family. Gene expression profiles revealed that MaRING2 was cold responsive and induced by abscisic acid (ABA) treatment during cold storage. In this study, the MaRING2 under control of the Cauliflower mosaic virus 35S (CaMV 35S) promoter was transformed to tobacco (Nicotiana benthamiana) using agrobacterium (Agrobacterium tumefaciens)-mediated transformation. The resultant MaRING2-overexpressing transgenic plants (35S:MaRING2) exhibited significantly increased tolerance to low temperatures and were hypersensitive to exogenous ABA in terms of germination and early seedling growth. In addition, overexpression of MaRING2 enhanced the expression of stress-responsive genes under normal (before cold stress) or cold conditions. These results demonstrate the biological role of MaRING2 in conferring cold tolerance. Taken together, these results suggest that MaRING2, a C3H2C3-type RING protein, is a positive regulator of the ABA-dependent stress response.
A comparison of field tolerance of 25 apple (Malus ×domestica) cultivars and 39 apple rootstocks to the pathogens Marssonina coronaria and Alternaria alternata apple pathotype was performed. Although most apple cultivars grown in China were susceptible or highly susceptible to both pathogens causing two diseases, considerable variation in the level of resistance to both pathogens was observed. Only three cultivars, Qinguan, Jiguan, and Xiangyanghong, exhibited resistance to both pathogens. Among the rootstocks tested, 30 of 39 (77%) were susceptible or highly susceptible to M. coronaria and 32 (82%) were susceptible to the A. alternata apple pathotype. Four rootstocks, ‘P.22’, ‘SH12’, ‘Za’ai 76’, and ‘Qingdao598’, were resistant to both pathogens. The correlation between resistance to both pathogens was highly significant in the 74 apple cultivars and rootstocks tested suggesting common genetic resistance factors to these two pathogens. Data represented horizontal resistance in the germplasm. The resistant local germplasm should be used in disease resistance breeding programs.
Landrace tea populations are important recourses for germplasm conservation and selection of elite tea clone cultivars. To understand their genetic diversity and use them effectively for breeding, two traditional landrace tea populations, Beichuan Taizicha (BCTZ) and Nanjiang Dayecha (NJDY), localized to northern Sichuan, were evaluated for morphological characters, simple sequence repeat (SSR)–based DNA markers and the contents of biochemical components. A wide range of morphological variation and a moderately high level of DNA polymorphism were observed from both BCTZ and NJDY. NJDY had on average, bigger leaves, larger flowers, higher total catechins (TCs), and greater gene diversity (GD) than BCTZ. Interestingly, samples from BCTZ had a wide range in the ratio of galloylated catechins to nongalloylated catechins (G/NG) (1.83–8.12, cv = 48.8%), whereas samples from NJDY were more variable in total amino acid (TAA) content (25.3–50.8 mg·g−1 dry weight) than those from BCTZ. We concluded that the two Camellia sinensis landrace populations are of great interest for both individual selection breeding and scientific studies.
This research was initiated to determine the response of apple (Malus ×domestica) fruit quality to sprays of zinc sulfate (ZnSO4) and sugar alcohol zinc. Two apple cultivars Fuji and Gala were evaluated, the leaf zinc (Zn) concentration of which were about 14.3 mg·kg−1 dry weight without Zn deficiency symptoms. The trees were sprayed with ZnSO4 and sugar alcohol zinc separately during four different developmental stages: 2 weeks before budbreak (P1), 3 weeks after bloom (P2), the termination of spring shoot growth (P3), and 4 weeks before harvest (P4). The fruit was harvested at maturity and analyzed for fruit quality and fruit Zn concentration. Zinc sprays during the four different developmental stages increased Zn concentration of peeled and washed fruit at harvest, without phytotoxicity. The treatments at stages P2 and P4 increased average fruit weight of ‘Gala’ and ‘Fuji’, respectively. The treatments at stages P1 and P4 increased the fruit firmness of ‘Gala’, while the treatments at stages P1 and P2 increased the fruit firmness of ‘Fuji’. The treatments at stages P1, P2, and P4 increased the soluble sugar and vitamin C of ‘Gala’ fruit, while the treatments at all the stages increased the soluble sugar and vitamin C of ‘Fuji’. And the effects of sugar alcohol zinc were equal and more pronounced than those of ZnSO4. Thus, Zn sprays at critical periods can improve fruit quality of apple trees, which show no Zn deficiency symptoms with leaf Zn concentration less than 15 mg·kg−1 dry weight.