Question

Role of plant hormones in seed ,fruit and grain formation

Answer 1

link.springer.com

The role of hormones in photosynthate partitioning and seed filling

Mark L Brenner, Nordine Cheikh

Plant hormones, 649-670, 1995

The movement of photoassimilates from sites of synthesis in leaf tissue (source) to the sites of net accumulation in a different tissue (sink) potentially can be regulated at numerous points. Regulation of the net flow of photoassimilates is an integrated process. It is generally accepted that the concentration gradient of photoassimilates between the source and sink is the primary determinant of the current rate of transport and pattern of partitioning (20). However, close examination of the various components involved in the overall process of partitioning indicates that endogenous plant hormones may serve as modulators of many of the specific rate limiting components. This chapter focuses on the involvement of plant hormones as natural regulators of partitioning of photoassimilates especially to developing seeds.

View at link.springer.com

Cited by 372

Related articles

All 4 versions

books.google.co.in

Patterns of fruit and seed production

THOMAS D Lee

Plant reproductive ecology: patterns and strategies. Oxford University Press, New York, 179-202, 1988

Ecological and evolutionary studies of plant reproduction have traditionally emphasized pollination and seed dispersal, while the development and maturation of fruits—and seeds within fruits—have received considerably less attention. In the past decade, however, a number of authors63, 88,891" 187 have emphasized the importance of patterns of fruit and seed maturation and abortion. These patterns influence the size and quality of the seed crop and are thus intimately related to plant fitness. 153,155 On any given plant, the number of ovules becoming seeds may be limited by (1) the number of ovules produced;(2) the quantity and quality of pollen transferred (pollen limitation);(3) the amount of nutrients and photosynthate available for allocation to fruits and seeds (resource limitation);(4) herbivores, predators, and disease; and (5) agents of the physical environment. 153 Clearly, this classification is oversimplified; distinguishing one limiting factor from another is often difficult. The distinction between pollen and resource limitation, for example, is often vague because these factors are interrelated in a complex way. 11, 12, 15194 While all of the factors listed above probably limit fruit and seed production at certain times, it is clear that in many species from various habitats fruit and seed production are typically resource limited. 148,153,187

This chapter focuses on plants in which fruit and seed production is resource limited. Assuming that such plants initiate a greater number of fruits and seeds than they can mature, this chapter addresses the question, What proximate factors determine which fruits and seeds mature and which do not? As reproductive abortion occurs at two levels, whole fruits and individual seeds within fruits, patterns of maturation and abortion at these two levels are described here in separate sections, fully recognizing that fruit and seed abortion are often related. Before describing the patterns, some physiological aspects of fruit and seed development are briefly reviewed and, in the final section of the chapter, some evolutionary implications of the patterns are discussed.

Answer 2

The plant hormone like auxin, giberllins are main factor influencing the growth of seed, fruit and grain formation.

EXPLANATION:

The production of auxin is by embryo which also stimulates the expansion of cells needed to form fruit. Fruit growth happens from an ovary, auxins also stimulates the food growth, ripening and abscission and hence food drop from the plant for dispersal. Auxins also stimulates the expansion of cells needed to form fruit. Auxin promotes the fruit development in absence of seeds in certain fruit like strawberries.