Skip to content
Login Register

#seed germination

11 public questions tagged with this topic.

plant Development - 1

Gibberellin-induced germination prominent in:

Gibberellin promotes germination by breaking seed dormancy and inducing hydrolytic enzymes mobilizing storage reserves toward growing embryo. Gibberellin-induced germination is particularly prominent in monocots especially cereals where embryo-synthesized GA diffuses to aleurone layer activating α-amylase gene expression via GAMYB Myb transcription factor degrading starchy endosperm releasing soluble sugars feeding embryo growth. This aleurone response is relatively minor in dicots where reserves reside in cotyledons. Malting in barley and brewing industries exploit GA-induced aleurone α-amylase production demonstrating agronomic importance and hormonal regulation of post-germinative reserve mobilization during seedling establishment phase.

Ref: Bewley, Plant Cell 1997; Taiz Plant Physiology Chap 27: GA-induced germination prominent in monocot aleurone via α-amylase.

View Details
Plant tissue culture 1

Gibberellins are mainly involved in:

Gibberellins are tetracyclic diterpenoid hormones with GA1 GA3 GA4 most bioactive functions centered on stem elongation, seed germination and floral transition. Biosynthesis proceeds from geranylgeranyl diphosphate via ent kaurene ent kaurenoic acid to GA12 catalyzed by terpene synthases and cytochrome P450 monooxygenases GA20 oxidase and GA3 oxidase. Signaling involves soluble receptor GID1 binding GA causing conformational change enabling interaction with DELLA repressors which are then ubiquitinated by SCF SLY1 GID2 complex and degraded via proteasome allowing transcription of growth genes. Physiologically gibberellins induce alpha-amylase and protease expression in barley aleurone via GAMYB transcription factor mobilizing starch reserves during germination antagonizing ABA. They promote internode elongation by enhancing cell division in intercalary meristem and wall extensibility through xyloglucan endotransglycosylase and expansin induction. In vitro GA3 at 0.1-1 mg per L elongates dwarf shoots, breaks bud dormancy, induces precocious flowering, though excessive level inhibits rooting and somatic embryo maturation requiring careful titration within medium composition.

Ref: Sun, Annu Rev Plant Biol 2008 GA-DELLA signaling; NCBI NBK10975 gibberellin pathway.

View Details
Plant Classification

Epigeal germination is characterized by

Epigeal germination involves substantial elongation of hypocotyl forming hook that pushes cotyledons above soil surface where they expand, become green, foliaceous and photosynthetic, as observed in common bean, castor and sunflower. Hypocotyl protective arch prevents plumule damage. In hypogeal germination epicotyl elongates, cotyledons remain underground serving as storage as in pea, gram and maize. Endosperm persistence unrelated to germination type, both show hypocotyl growth but magnitude differs. Epigeal strategy favours rapid autotrophy in open habitats with limited seed reserves and is common in many dicots with epigeal cotyledons.

Ref: NCERT Class 11 Biology, Seed germination epigeal hypogeal; Bewley Seed Germination textbook

View Details
Phytohormone ALL PYQS

GA induces α‑amylase expression in barley in the:

Pick C: Aleurone layer. Thinking through Phytohormone ALL step by step rules out the lookalikes and leaves Aleurone layer. Skip these: A) Embryo; B) Endosperm; D) Coleoptile. For hormones and genes, match the molecule or gene to its real role, not a neighboring pathway.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

View Details
Striglactone

Which parasitic weed seed germination is stimulated by strigolactones?

The right choice is B: Striga. In Striglactone, that matches how the process or concept actually works — the other choices mix up related ideas or use the wrong mechanism. Skip these: A) Cuscuta; C) Rafflesia; D) Viscum. A quick check: if an option needs energy, pumps, or the opposite direction of movement, ask whether that really applies.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

View Details
Gibberellins

Hormone antagonistic to GA during seed germination is:

Go with C — ABA. Under Gibberellins, this is the standard explanation you’d use in class: it names the real driver or definition, while the rest are nearby but wrong. Not these: A) Auxin; B) Ethylene; D) Cytokinin. When two options sound similar, choose the one that matches the textbook definition most tightly.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

View Details