• Journal of Plant Biotechnology
• /
• 제47권1호
• /
• pp.26-39
• /
• 2020

In maize, immature embryos (IEs) are highly regenerative explants most suitable for producing high frequencies of plantlet regeneration in vitro. Apart from media, explants, and hormones, genotypic variation also influences in vitro characters to a great extent. In the present study, IEs were used to study the distinctive effect of variation of size/stage and hormones in different genotypes on five in vitro characters viz., frequency of callus induction, growth rate of total callus, frequency of E. callus induction, and volume and number of regenerated plantlets. LS medium with different concentrations of 2,4-D (0.5, 1.5, 2.5, 4.0 and 5.0 mg/L) were used to study the former four in vitro characters, and medium with 6-benzylaminopurine and kinetin (0.5 mg/L, each) was used for plantlet regeneration. IEs of 1.0, 1.5, 2.0, 2.5 and 3.0 mm in size were isolated from four inbred lines viz., NM74C, NM81A, NM5883 and NM5884. Two-way ANOVA revealed that explant size and genotypes, as well as hormonal concentrations showed significant effects on in vitro characters. Two millimeter IEs were found to be suitable for in vitro cultures. LS medium with 1.5 mg/L 2,4-D and LS with BAP and Kn (0.5 mg/L, each) were found to be the best hormonal concentrations for callus induction, maintenance, and regeneration, respectively. Among the four genotypes, NM81A and NM5883 yielded more non-embryogenic and Type I E. calli. In contrast, NM74C and NM5884 yielded more highly regenerative Type II calli. Inbred line NM5884 was found to be the best among these four genotypes.

• 농업과학연구
• /
• 제44권2호
• /
• pp.196-210
• /
• 2017

The synergistic effect on phosphate solubilization of single- and co-inoculation of two phosphate solubilizing bacteria, Burkholderia cepacia (C1) and Alcaligenes aquatilis (H6), was assessed in liquid medium and maize plants. Co-inoculation of two strains was found to release the highest content of soluble phosphorus (309.66 ?g/mL) into the medium, followed by single inoculation of B. cepacia (305.49 ?g/mL) and A. aquatilis strain (282.38 ?g/mL). Based on a plant growth promotion bioassay, co-inoculated maize seedlings showed significant increases in shoot height (75%), shoot fresh weight (93.10%), shoot dry weight (84.99%), root maximum length (55.95%), root fresh weight (66.66%), root dry weight (275%), and maximum leaf length (81.53%), compared to the uninoculated control. In a field experiment, co-inoculated maize seedlings showed significant increases in cob length (136.92%), number of grain/cob (46.68%), and grain weight (67.46%) over control. In addition, single inoculation of maize seedlings also showed improved result over control. However, there was no significant difference between single inoculation of either bacterial strains and co-inoculation of these two bacterial strains in terms of phosphate solubilization index, phosphorous release, pH of the media, and plant growth parameters. Thus, single inoculation and co-inoculation of these bacteria could be used as biofertilizer for improving maize growth and yield.

• 생명과학회지
• /
• 제16권4호
• /
• pp.699-703
• /
• 2006

옥수수(Zea mays)는 단성화 식물로서 암꽃과 수꽃이 한 식물체내에 분리되어서 존재하며 수정시 이질성을 높이는 방향으로 진화되었다. 암꽃과 수꽃 각각은 단성화 상태로 분화하기 전에 한 개의 암술과 세 개의 수술 원시세포가 동일하게 형성된다. 옥수수가수꽃으로 분화할 때는 암술 원시세포에서 세포사멸 현상이 일어나는데 이것은 TASSELSEED 유전자들에 의해 매개된다. 이와 대조적으로 암꽃의 암술에서는 TASSELSEED 유전자들에 의한 세포사멸이 억제되는데 여기에는 SILKLESS1 유전자가 관여한다. 한편, 암꽃의 수술에서는 세포주기 멈춤 현상이 오랜 시간 지속되다가 결국에는 수술이 죽게 된다. 이때 세포주기를 조절하는 유전자인 CYCLIN B 와 WEE1 유전자가 이 과정에 참여한다. 이와 더불어, 지베렐린 생합성의 시간적 공간적 조절이 수술의 세포주기 멈춤의 원인이 된다. 본 총설에서는 옥수수의 성 결정 과정 중에 일어나는 세포사멸, 세포 방어, 세포주기 멈춤에 대하여 분자세포 발생 생물학 및 유전학적인 견지에서 고찰하였다.

• 한국토양비료학회지
• /
• 제33권2호
• /
• pp.85-91
• /
• 2000

옥수수의 항산화 활성에 대한 N-P-K의 시비의 효과를 알아보고자, 찰옥 2호와 수원 19호 두 품종을 대상으로 시비량에 따른 옥수수의 항산화 활성과 tocopherols, 페놀화합물, carotenoids의 함량을 분석하였다. 시비 수준은 N, P, K 각각에 대한 표준 시비량과 이의 1/2 및 2배 그리고 무비이었다. 찰옥2호의 항산화 활성은 19.0~22.2%로, 수원19호보다 높았다. 찰옥 2호의 항산화 활성은 표준 시비구에서 가장 높았으나, 처리간의 유의성은 없었고, 수원19호의 항산화활성과 항산화 성분 함량은 질소 2배 시용구에서 높았다. Tocopherols, 페놀화합물, carotenoids의 함량은 찰옥2호의 경우 각각 30.0~38.1, 104.7~118.8, $0.1{\mu}gml^{-1}$였고, 수원19호는 각각 16.7~20.1, 59.9~72.7, $35.5{\sim}50.0{\mu}gml^{-1}$로 항산화 활성과 마찬가지로 변이폭이 작고, 시비량에 따른 뚜렷한 경향을 보이지 않았다. ASI와 항산화 활성은 옥수수의 수량과 정상관이 있었으며, 항산화 활성은 tocopherols, 페놀화합물의 함량과 정상관이 있었으나 carotenoids와는 상관관계가 없었다. 옥수수의 항산화 활성과 항산화성분 함량은 품종간 변이의 영향이 시비량에 의한 환경변이의 영향보다 큰 것으로 보인다.

• 한국생명과학회:학술대회논문집
• /
• 한국생명과학회 2001년도 10주년 기념 국제학술 심포지움 및 추계학술대회
• /
• pp.103-103
• /
• 2001

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2001년도 춘계 학술대회지
• /
• pp.240-241
• /
• 2001

• 한국생명과학회:학술대회논문집
• /
• 한국생명과학회 2000년도 제29회 국제학술심포지움 및 추계학술대회
• /
• pp.24-24
• /
• 2000

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2020년도 추계학술대회
• /
• pp.135-135
• /
• 2020

• 한국환경과학회지
• /
• 제19권12호
• /
• pp.1323-1334
• /
• 2010

The effect of nitric oxide (NO) on antioxidant system and protective mechanism against oxidative stress under UV-B radiation was investigated in leaves of maize (Zea mays L.) seedlings during 3 days growth period. UV-B irradiation caused a decrease of leaf biomass including leaf length, width and weight during growth. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated UV-B stress induced growth suppression. NO donor permitted the survival of more green leaf tissue preventing chlorophyll content reduction and of higher quantum yield for photosystem II than in non-treated controls under UV-B stress, suggesting that NO has protective effect on chloroplast membrane in maize leaves. Flavonoids and anthocyanin, UV-B absorbing compounds, were significantly accumulated in the maize leaves upon UV-B exposure. Moreover, the increase of these compounds was intensified in the NO treated seedlings. UV-B treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide ($H_2O_2$) in maize leaves, while NO donor prevented UV-B induced increase in the contents of malondialdehyde (MDA) and $H_2O_2$. These results demonstrate that NO serves as antioxidant agent able to scavenge $H_2O_2$ to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, catalase (CAT) and ascorbate peroxidase (APX) in maize leaves in the presence of NO donor under UV-B stress were higher than those under UV-B stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3- oxide (PTIO), a specific NO scavenger, to the maize leaves arrested NO donor mediated protective effect on leaf growth, photosynthetic pigment and free radical scavenging activity. However, PTIO had little effect on maize leaves under UV-B stress compared with that of UV-B stress alone. $N^{\omega}$-nitro-L-arginine (LNNA), an inhibitor of nitric oxide synthase (NOS), significantly increased $H_2O_2$ and MDA accumulation and decreased antioxidant enzyme activities in maize leaves under UV-B stress. This demonstrates that NOS inhibitor LNNA has opposite effects on oxidative resistance. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative stress induced by UV-B radiation and thus confer UV-B tolerance.

• 한국작물학회지
• /
• 제48권5호
• /
• pp.392-396
• /
• 2003

Maysin, a C-glycosylflavone, was isolated from the silks of maize, Zea mays L. The ESI mass spectrum indicates that molecular weight of maysin is $577\textrm{M}^+$m/z, and the ether-linked sugar is rhamnose, $431\textrm{M}^+$m/z (MW$^{+}$-146). The DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical scavenging activity of maysin was higher than that of rutin. However, as compared with its aglycon luteolin, maysin showed the relatively moderate DPPH scavenging activity mainly due to the glycosylation of two sugars moieties, keto-fucose and rhamnose. In the in vitro cytotoxicity test against the five human tumor cell lines such as lung (A549), ovarian (SK-OV-3), melanoma (SK-MEL-2), central nerve system (XF-489), and colon (HCT-15), maysin exhibited the relatively weaker activities than cisplatin. The $\textrm{ED}_{50}$ values of maysin were 62.24, 43.18, 16.83, 37.22, and 32.09/$m\ell$, respectively. Result suggests that maysin is a potential cytotoxicity compound, particularly for human colon, central nerve system, and melanoma tumors.s.